Installation

& Servicing

Instructions

THESE INSTRUCTIONSTO BE RETAINEDBY USER

Vokèra is a licensed member of the Benchmark schemewhich aims to improve the standards of installation and commissioning of domestic hot water systems in the UK.

Compact Standard efficiency combi boiler

ContentsDesign principles and operating sequence Page1.1 Principle components 21.2 Central heating mode 21.3 Hot water mode 21.4 Safety devices 21.5 Frost protection 2

Technical data Page2.1 Central heating 32.2 Domestic hot water 32.3 Gas pressure 32.4 Expansion vessel 32.5 Dimensions 32.6 Clearances 32.7 Connections 32.8 Electrical 32.9 Flue details 32.10 Efficiency 32.11 Pump duty 4

General requirements (UK) Page3.1 Related documents 53.2 Location of appliance 53.3 Gas supply 53.4 Flue system 53.5 Air supply 53.6 Water circulation 53.6.1 Pipework 63.6.2 Automatic by-pass 63.6.3 Drain cocks 63.6.4 Air release points 63.6.5 Expansion vessel 63.6.6 Filling point 63.6.7 Low pressure sealed system 63.6.8 Frequent filling 63.7 Electrical supply 63.8 Showers 63.9 Mounting on a combustible surface 73.10 Timber framed building 73.11 Inhibitors 7

General requirements (EIRE) Page3.A1 Related documents 73.A2 Location of appliance 73.A3 Gas supply 73.A4 Flue system 73.A5 Air supply 83.A6 Water circulation 83.A6.1 Pipework 83.A6.2 Automatic by-pass 83.A6.3 Drain cocks 83.A6.4 Air release points 83.A6.5 Expansion vessel 83.A6.6 Filling point 83.A6.7 Low pressure sealed system 83.A6.8 Frequent filling 83.A7 Electrical supply 83.A8 Showers 83.A9 Mounting on a combustible surface 83.A10 Timber framed building 83.A11 Inhibitors 83.A12 Declaration of conformity 8

Installation Page4.1 Delivery 94.2 Contents 94.3 Unpacking 94.4 Preparation for mounting the appliance 94.4.1 Important 94.4.2 Flue restrictor ring 94.5 Fitting the flue 94.5.1 Concentric horizontal flue 94.5.2 Concentric vertical flue 114.5.3 Twin flue system 114.6 Connecting the gas and water 134.6.1 Gas 134.6.2 Flow and return 144.6.3 Safety valve 144.6.4 Cold water inlet 144.6.5 Hot water outlet 144.7 Electrical connections 144.7.1 Casing removal 144.7.2 Electrical connection 144.7.3 Connecting the mains (230V) input 15

Commissioning Page5.1 Gas supply installation 165.2 The heating system 165.3 Initial filling of the system 165.4 Initial flushing 165.5 Filling the hot water system 165.6 Pre-operation checks 165.7 Initial lighting 165.8 Checking burner pressures 165.9 Final flushing of the heating system 175.9.1 Inhibtors 175.10 Setting the flow temperature 175.11 Setting the system design pressure 175.12 Regulating the central heating system 175.13 Regulating the domestic hot water 175.14 Final checks 175.15 Instructing the user 17

Servicing instructions Page6.1 General 186.2 Routine annual servicing 186.3 Replacement of components 186.4 De-scaling main heat exchanger 186.5 Component removal procedure 186.6 Pump head 186.7 Safety valve 186.8 Automatic air release valve 196.9 Water pressure switch 196.10 Domestic water flow switch 196.11 Pressure gauge 196.12 Primary and secondary thermistors 196.13 High limit thermostat 196.14 PCB 206.15 Integral time switch 206.16 Gas valve 206.17 Burner, injectors and spark/sense electrode 206.18 Flue fan 216.19 Heat exchanger 216.20 Air pressure switch 216.21 Expansion vessel 216.22 Expansion vessel (removal) 21

Checks, adjustments and fault finding page7.1 Checking appliance operation 227.2 At rest mode 227.3 Hot water mode 227.4 Heating mode 227.5 Frost protection mode 227.6 Burner pressure settings 227.6.1 Setting the maximum DHW gas pressure 237.6.2 Setting the minimum DHW gas pressure 237.6.3 Setting the max & min CH burner pressures 237.7 Combustion analysis test 237.8 Checking the expansion vessel 237.9 Electro-mechanical faults 237.10 Possible installation faults 247.11 Electrical checks 247.11.1 Earth continuity test 247.11.2 Short circuit test 247.11.3 Polarity check 247.11.4 Reversed polarity or supply fault 247.11.5 Resistance to earth check 247.11.6 Fuses 247.12 Fault finding 24-31

Wiring diagrams Page8.1 Connection of a room thermostat 328.2 Connection of an external time clock 32Functional flow diagram 33-34

Exploded diagrams PageTable 1 35Table 2 36Table 3 37Table 4 38Table 5 39

L.P.G. instructions Page10.1 Technical data 4010.2 Related documents 4010.3 Gas supply 4010.4 Gas supply installation 4010.5 Burner pressures 4010.5.1 Setting the maximum DHW gas pressure 4010.5.2 Setting the minimum DHW gas pressure 4010.5.3 Setting the max & min CH burner pressures 40

REAR FLUE Page11.1 Fitting the flue 41

1Compact

INTRODUCTION

Fig.1 General Layout

1 Flue Analysis Test Point2 Pressure Tube Negative3 Fan Assembly4 Heat Exchanger5 Secondary thermistor6 Combustion chamber7 Burner8 Expansion vessel9 Water pressure switch10 Domestic Hot Water Flow Switch11 Gas Valve12 Timeclock13 CH position14 Fault indicator led15 Mode selector switch16 DHW position17 Pressure gauge18 Safety valve19 Pump20 Auto air vent21 Electrode22 High limit thermistor23 Primary thermistor24 Air chamber (with cover removed)25 Air pressure switch26 Auto by pass (fig. 2)27 Water flow restrictor (fig. 2)

The Vokera Compact range of appliances are combinedcentral heating and domestic hot water boilers, which –by design – incorporates full sequence electronic ignition,circulating pump, expansion vessel, safety valve,pressure gauge, automatic by-pass, and mechanical timeclock.

Compact is produced as a room sealed appliance, suitablefor wall mounting applications only. Compact is provided

with a fan powered flue outlet with an annular co-axialcombustion air intake that can be rotated – horizontally –through 360 degrees for various horizontal or verticalapplications, and can also be converted for use with arear flue outlet. Compact can also be used with theVokera twin flue system.

This appliance is designed primarily for use with sealedsystems; consequently it is not intended for use on anopen vented system.

Fig. 1

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1 2

3

4

5

6

7

8

9

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1118

19

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2 Compact

SECTION 1 DESIGN PRINCIPLES AND OPERATING SEQUENCE

Fig. 2

1.1 PRINCIPLE COMPONENTS● A fully integrated, electronic control board fea-

turing mode selection switch, full sequence-electronic ignition, temperature control system,and appliance status indicator.

● A BI-thermal gas to water heat exchanger.● A multi-functional gas valve.● Two-stage, primary water pressure switch.

Integral pump, expansion vessel, pressure re-lief valve, pressure gauge, domestic water flowswitch, fan, differential air pressure switch, andtime clock.

MODES OF OPERATION

1.2 CENTRAL HEATING MODEWhen there is a request for central heating via thetime-clock and/or any external controls, the pumpand fan are started, the fan proves the differentialair pressure switch which in-turn, allows an ignitionsequence to begin.Ignition is sensed by the electronic circuitry toensure flame stability at the burner. Once suc-cessful ignition has been achieved the applianceoperates al 75% of maximum for a fifteen-minuteperiod, and thereafter the appliance operates onmaximum output until the desired temperaturesetting is reached.

Once the desired temperature is reached, theburner will modulate to maintain that tempera-ture, however should the temperature within theappliance continue to rise, the burner will shutdown and the boiler will perform a three-minuteanti-cycle (timer delay).

1.3 HOT WATER MODEWhen there is a demand for domestic hot waterthe domestic hot water flow switch is proved bythe flow of water through the appliance, thisallows the fan to run, the fan proves the differen-tial air pressure switch which in-turn, allows anignition sequence to begin.

Ignition is sensed by the electronic circuitry toensure flame stability at the burner. Oncesuccessful ignition has been achieved the appli-ance will modulate burner gas pressure to main-tain the desired water temperature, should thetemperature of the domestic hot water exceedthe temperature setting by 5 ºC the burner willshut down until the water temperature dropsbelow the required setting.

1.4 SAFETY DEVICESIn both central heating and domestic hot watermodes, safe operation is ensured by.● A water pressure switch that monitors the sys-

tem pressure and will deactivate the pump andprevent burner ignition should the pressure orprimary flow rate fall below the rated tolerance.

● Differential air pressure switch that checks thecorrect operation of the fan and flue therebypreventing or interrupting burner operation.

● A high limit thermostat that overrides the con-trol circuit to prevent or interrupt burner ignition.

● A safety valve which releases excess pressurefrom the primary circuit.

1.5 FROST PROTECTIONThe appliance has built-in frost protection thatallows the pump to operate if the appliance tem-perature drops to 7 ºC, should the temperaturecontinue to drop the burner will light until theprimary circuit temperature exceeds 30 ºC.

return flow hwoutlet

coldinlet

27

5

910

26

19

8

23

4

20

18

3Compact

SECTION 2 TECHNICAL DATA

Ref. Condition 15 °C , 1013,25 mbar, dry gasNOTE: L.P.G. data refer to section 10

Compact 24 Compact 282.1 Central heatingHeat input (kW) 26.3 31.0Heat output (maximum) kW 24.0 28.0Heat output (minimum) kW 9.4 10.5Minimum working pressure 0,5 bar 0,5 barMaximum working pressure 3.0 bar 3.0 barMinimum flow rate 350 l/h 350 l/h

2.2 Domestic hot waterHeat input (kW) 26.3 31.0Heat output (maximum) kW 24.0 28.0Heat output (minimum) kW 8.2 8.7Flow rate (35 °C rise) 9.8 l/min 11.5 l/minMaximum inlet pressure 6.0 bar 6.0 barMinimum inlet working pressure 0.15 bar 0.15 barMinimum flow rate 2 l/min. 2 l/min.

2.3 Gas pressuresInlet pressure G20 20.0 mbar 20.0 mbarMaximum burner pressure 10.1 mbar 10.2 mbarMinimum burner pressure (central heating) 1.9 mbar 1.9 mbarMinimum burner pressure (domestic hot water) 1.5 mbar 1.3 mbarGross rate (maximum) 2.78 m3/h 3.28 m3/hInjectors size 12 x 1.35 mm 14 x 1.35 mm

2.4 Expansion vesselCapacity 8 litres 8 litresMaximum system volume 76 litres 76 litresPre-charge pressure 1.0 bar 1.0 bar

2.5 DimensionsHeight 740 mm 740 mmWidth 400 mm 450 mmDepth 328 mm 328 mmDry weight 32 kg 34 kg

2.6 ClearancesLeft side 50 mm 50 mmRight side 12 mm 12 mmTop 150 mm from casing or 25 mm above flue elbow, whichever is applicableBottom 150 mm 150 mmFront 600 mm 600 mm

2.7 ConnectionsFlow & return 22 mm 22 mmHot & cold water connections 15 mm 15 mmGas 15 mm 15 mmSafety valve 15 mm 15 mm

2.8 ElectricalVoltage 230V/~ 50hz 230V/~ 50hzPower consumption 125 W 125 WInternal fuse 2 A 2 APCB fuse 2 AF 2 AFExternal fuse 3 A 3 A

2.9 Flue detailsMaximum horizontal flue length (concentric) 4.25 m 3.4 mMaximum vertical flue length (concentric) 5 m 4.2 mMaximum twin flue length (horizontal or vertical) 14 m + 14 m 14 m + 14 mMaximum rear flue length (see section 11) 1.0 m 1.0 m

2.10 EfficiencySEDBUK Band “D” Band “D”

4 Compact

2.11 PUMP DUTYFig. 3 shows the flow rate available – afterallowing for pressure loss through theappliance – against system pressure loss.When using this graph apply only thepressure loss of the system. The graph isbased on a 20 ºC temperature differential.

Fig. 3

Fig. 4

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er p

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ure

(m

bar

)

Litres Per Hour (x100)

100

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300

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600

0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400

SECTION 3 GENERAL REQUIREMENTS (UK)

Key Location Minimum distance

A Below an opening (window, air-brik, etc.) 300 mmB Above an opening (window, air-brik, etc.) 300 mmC To the side of an opening (window, air-brik, etc.) 300 mmD Below gutter, drain-pipe, etc. 75 mmE Below eaves 200 mmF Below balcony, car-port roof, etc. 200 mmG To the side of a soil/drain-pipe, etc. 150 mmH From internal/external corner or boundary 300 mmI Above ground, roof, or balcony level 300 mmJ From a surface or boundary facing the terminal 600 mmK From a terminal facing a terminal 1200 mmL From an opening in the car-port into the building 1200 mmM Vertically from a terminal on the same wall 1500 mmN Horizontally from a terminal on the same wall 300 mmP From a structure to the side of the vertical terminal 300 mmQ From the top of the vertical terminal to the roof flashing As determined by the fixed collar

of the vertical terminal

.

5Compact

This appliance must be installed by a competentperson in accordance with the Gas Safety(Installation & Use) Regulations.

3.1 RELATED DOCUMENTSThe installation of this boiler must be in accordancewith the relevant requirements of the Gas Safety(Installation & Use) Regulations, the local buildingregulations, the current I.E.E. wiring regulations,the bylaws of the local water undertaking, theBuilding Standards (Scotland) Regulation, andBuilding Standards (Northern Ireland)Regulations.It should be in accordance also with any relevantrequirements of the local authority and the relevantrecommendations of the following British StandardCodes of Practice.

3.2 LOCATION OF APPLIANCEThe appliance may be installed in any room orinternal space, although particular attention isdrawn to the requirements of the current I.E.E.wiring regulations, and in Scotland, the electricalprovisions of the Building Regulations, withrespect to the installation of the appliance in aroom or internal space containing a bath or shower.

When an appliance is installed in a room orinternal space containing a bath or shower, theappliance or any control pertaining to it must notbe within reach of a person using the bath orshower.The location chosen for the appliance must permitthe provision of a safe and satisfactory flue andtermination. The location must also permit anadequate air supply for combustion purposesand an adequate space for servicing and aircirculation around the appliance. Where theinstallation of the appliance will be in an unusuallocation special procedures may be necessary,BS 6798 gives detailed guidance on this aspect.A compartment used to enclose the appliancemust be designed and constructed specificallyfor this purpose. An existing compartment/cupboard may be utilised provided that it ismodified to suit.Details of essential features of compartment/cupboard design including airing cupboardinstallations are given in BS 6798. This applianceis not suitable for external installation.

3.3 GAS SUPPLYThe gas meter – as supplied by the gas supplier– must be checked to ensure that it is of adequatesize to deal with the maximum rated input of allthe appliances that it serves. Installation pipesmust be fitted in accordance with BS 6891.Pipe work from the meter to the appliance mustbe of adequate size. Pipes of a smaller size thanthe appliance gas inlet connection must not beused. The installation must be tested forsoundness in accordance with BS6891.If the gas supply serves more than one appliance,it must be ensured that an adequate supply ismaintained to each appliance when they are inuse at the same time.

3.4 FLUE SYSTEMThe terminal should be located where the dispersalof combustion products is not impeded and withdue regard for the damage and discoloration thatmay occur to building products located nearby.The terminal must not be located in a place whereit is likely to cause a nuisance (fig. 4).In cold and/or humid weather, water vapour maycondense on leaving the terminal; the effect ofsuch pluming must be considered.

BS 5440 PART 1 FLUES

BS 5440 PART 2 FLUES AND VENTILATION

BS 5449 PART 1 FORCED CIRCULATION HOT WATER SYSTEMS

BS5546 INSTALLATION OF GAS HOT WATER SUPPLIES FOR DOMESTIC PURPOSES(2ND FAMILY GASES)

BS 6798 BOILERS OF RATED INPUT NOT EXCEEDING 60kW

BS 6891 LOW PRESSURE INSTALLATION PIPES

BS 7074 PART 1 APPLICATION, SELECTION, AND INSTALLATION OF EXPANSION VESSELS ANDANCILLARY EQUIPMENT FOR SEALED WATER SYSTEMS

If installed less than 2 m above a pavement orplatform to which people have access (includingbalconies or flat roofs) the terminal must beprotected by a guard of durable material. Theguard must be fitted centrally over the terminal.Refer to BS 5440 Part 1, when the terminal is 0.5metres (or less) below plastic guttering or 1 metre(or less) below painted eaves.

3.5 AIR SUPPLYThe following notes are intended for generalguidance only.This appliance is a room-sealed, fan-flued boiler,consequently it does not require a permanent airvent for combustion air supply.When installed in a cupboard or compartment,ventilation for cooling purposes is also notrequired.

3.6 WATER CIRCULATIONDetailed recommendations are given in BS 5449Part 1 and BS 6798. The following notes are forgeneral guidance only.

6 Compact

Fig. 5a

3.6.7 LOW PRESSURE SEALED SYSTEMAn alternative method of filling the system wouldbe from an independent make-up vessel or tankmounted in a position at least 1 metre above thehighest point in the system and at least 5 metresabove the boiler (fig. 5a).The cold feed from the make-up vessel or tankmust be fitted with an approved non-return valveand stopcock for isolation purposes. The feedpipe should be connected to the return pipe asclose to the boiler as possible.

3.6.8 FREQUENT FILLINGFrequent filling or venting of the system may beindicative of a leak. Care should be taken duringthe installation of the appliance to ensure allaspects of the system are capable of withstandingpressures up to at least 3 bar.

3.7 ELECTRICAL SUPPLYThe appliance is supplied for operation on 230V@ 50Hz electrical supply; it must be protectedwith a 3-amp fuse. The method of connection tothe mains electricity supply must allow forcomplete isolation from the supply. The preferredmethod is by using a double-pole switch with acontact separation of at least 3 mm. The switchmust only supply the appliance and itscorresponding controls, i.e. time clock, roomthermostat, etc. Alternatively an un-switchedshuttered socket with a fused 3-pin plug bothcomplying with BS 1363 is acceptable.

3.8 SHOWERSIf the appliance is intended for use with a shower,the shower must be thermostatically controlledand be suitable for use with a combination boiler.

3.6.1 PIPEWORKIt is recommended that copper tubing to BS 2871Part 1 is used in conjunction with soldered capillaryjoints.Where possible pipes should have a gradient toensure air is carried naturally to air release pointsand that water flows naturally to drain cocks.Except where providing useful heat, pipes shouldbe insulated to avoid heat loss and in particular toavoid the possibility of freezing. Particular attentionshould be paid to pipes passing through ventilatedareas such as under floors, loft space, and voidareas.

3.6.2 AUTOMATIC BY-PASSThe appliance has a built-in automatic by-pass,consequently there is no requirement for anexternal by-pass, however the design of thesystem should be such that it prevents boiler‘cycling’.

3.6.3 DRAIN COCKSThese must be located in accessible positions tofacilitate draining of the appliance and all waterpipes connected to the appliance. The draincocks must be manufactured in accordance withBS 2879.

3.6.4 AIR RELEASE POINTSThese must be positioned at the highest points inthe system where air is likely to be trapped. Theyshould be used to expel trapped air and allowcomplete filling of the system.

3.6.5 EXPANSION VESSELThe appliance has an integral expansion vesselto accommodate the increased volume of waterwhen the system is heated. It can accept up to 8litres of expansion from within the system,generally this is sufficient, however if the systemhas an unusually high water content, it may benecessary to provide additional expansioncapacity (see section 6.19).

3.6.6 FILLING POINTA method for initial filling of the system andreplacing water lost during servicing etc. must beprovided. This method of filling must comply withthe current Water Supply (Water Fittings)Regulations 1999 and Water Bylaws 2000(Scotland). Fig. 5 shows an accepted method.

Fig. 5

control valve

temporaryconnection

control valve

supply pipe

double checkvalve

flow/returnpipe

Make-up vesselor tank

Automaticair-vent

Non-returnvalve

Stopcock

5.0

met

res

min

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Heatingreturn

7Compact

Fig. 6

3.9 MOUNTING ON A COMBUSTIBLE SURFACEIf the appliance is to be fitted on a wall ofcombustible material, a sheet of fireproof materialmust protect the wall.

3.10 TIMBER FRAMED BUILDINGIf the appliance is to be fitted in a timber framedbuilding, it should be fitted in accordance with theInstitute of Gas Engineers publication (IGE/UP/7) ‘Guide for Gas Installations in Timber FrameBuildings’.

3.11 INHIBITORSVokera recommend that a neutral inhibitor isused to protect the heating system from theeffects of corrosion and/or electrolytic action.The inhibitor must be administered in strictaccordance with the manufacturers* instructions.

*Fernox and Sentinel manufacture products thathave proved suitable for use with Vokeraappliances. Vokera Ltd. cannot comment on thesuitability of any other such product with ourappliances.

SECTION 3A GENERAL REQUIREMENTS (EIRE)

This appliance must be installed by a competentperson in accordance with and defined by, theStandard Specification (Domestic GasInstallations) Declaration (I.S. 813).

3A.1 RELATED DOCUMENTSThe installation of this boiler must be in accordancewith the relevant requirements of the local buildingregulations, the current ETCI National Rules forElectrical Installations, and the bylaws of thelocal water undertaking.It should be in accordance also with any relevantrequirements of the local and/or district authority.

3A.2 LOCATION OF APPLIANCEThe appliance may be installed in any room orinternal space, although particular attention isdrawn to the requirements of the current ETCINational Rules for Electrical Installations, andI.S. 813, Annex K.When an appliance is installed in a room or internalspace containing a bath or shower, the applianceor any control pertaining to it must not be withinreach of a person using the bath or shower.The location chosen for the appliance must permitthe provision of a safe and satisfactory flue andtermination. The location must also permit anadequate air supply for combustion purposesand an adequate space for servicing and aircirculation around the appliance. Where theinstallation of the appliance will be in an unusuallocation special procedures may be necessary,refer to I.S. 813 for detailed guidance on thisaspect. A compartment used to enclose theappliance must be designed and constructedspecifically for this purpose. An existingcompartment/cupboard may be utilised providedthat it is modified to suit.

This appliance is not suitable for externalinstallation.

3A.3 GAS SUPPLYThe gas meter – as supplied by the gas supplier– must be checked to ensure that it is of adequatesize to deal with the maximum rated input of allthe appliances that it serves. Installation pipesmust be fitted in accordance with I.S. 813.Pipe work from the meter to the appliance mustbe of adequate size. Pipes of a smaller size thanthe appliance gas inlet connection must not beused. The installation must be tested forsoundness in accordance with I.S. 813.If the gas supply serves more than one appliance,it must be ensured that an adequate supply ismaintained to each appliance when they are inuse at the same time.

3A.4 FLUE SYSTEMThe terminal should be located where the dispersalof combustion products is not impeded and withdue regard for the damage and discoloration thatmay occur to building products located nearby.The terminal must not be located in a place whereit is likely to cause a nuisance (see I.S. 813).In cold and/or humid weather, water vapour maycondense on leaving the terminal; the effect ofsuch pluming must be considered.If installed less than 2 m above a pavement orplatform to which people have access (includingbalconies or flat roofs) the terminal must beprotected by a guard of durable material. Theguard must be fitted centrally over the terminal.Refer to I.S. 813, when the terminal is 0.5 metres(or less) below plastic guttering or 1 metre (orless) below painted eaves.

3 5

1 5 0 9 5

8 5

1 5 0

8 Compact

3A.5 AIR SUPPLYThe following notes are intended for generalguidance only. This appliance is a room-sealed,fan-flued boiler, consequently it does not requirea permanent air vent for combustion air supply.When installed in a cupboard or compartment,ventilation for cooling purposes is also notrequired.

3A.6 WATER CIRCULATIONSpecific recommendations are given in I.S. 813.The following notes are for general guidanceonly.

3A.6.1 PIPEWORKIt is recommended that copper tubing be used inconjunction with soldered capillary joints.Where possible pipes should have a gradient toensure air is carried naturally to air release pointsand that water flows naturally to drain cocks.Except where providing useful heat, pipes shouldbe insulated to avoid heat loss and in particular toavoid the possibility of freezing. Particular attentionshould be paid to pipes passing through ventilatedareas such as under floors, loft space, and voidareas.

3A.6.2 AUTOMATIC BY-PASSThe appliance has a built-in automatic by-pass,consequently there is no requirement for anexternal by-pass, however the design of thesystem should be such that it prevents boiler‘cycling’.

3A.6.3 DRAIN COCKSThese must be located in accessible positions tofacilitate draining of the appliance and all waterpipes connected to the appliance.

3A.6.4 AIR RELEASE POINTSThese must be positioned at the highest points inthe system where air is likely to be trapped. Theyshould be used to expel trapped air and allowcomplete filling of the system.

3A.6.5 EXPANSION VESSELThe appliance has an integral expansion vesselto accommodate the increased volume of waterwhen the system is heated. It can accept up to 8litres of expansion from within the system,generally this is sufficient, however if the systemhas an unusually high water content, it may benecessary to provide additional expansioncapacity (see section 6.19).

3A.6.6 FILLING POINTA method for initial filling of the system andreplacing water lost during servicing etc. hasbeen provided. You should ensure this method offilling complies with the local water authorityregulations.

3A.6.7 LOW PRESSURE SEALED SYSTEMAn alternative method of filling the system wouldbe from an independent make-up vessel or tankmounted in a position at least 1 metre above thehighest point in the system and at least 5 metresabove the boiler (fig. 5).

The cold feed from the make-up vessel or tankmust be fitted with an approved non-return valveand stopcock for isolation purposes. The feedpipe should be connected to the return pipe asclose to the boiler as possible.

3A.6.8 FREQUENT FILLINGFrequent filling or venting of the system may beindicative of a leak. Care should be taken duringthe installation of the appliance to ensure allaspects of the system are capable of withstandingpressures up to at least 3 bar.

3A.7 ELECTRICAL SUPPLYThe appliance is supplied for operation on 230V@ 50Hz electrical supply; it must be protectedwith a 3-amp fuse. The method of connection tothe mains electricity supply must allow forcomplete isolation from the supply. The preferredmethod is by using a double-pole switch with acontact separation of at least 3 mm. The switchmust only supply the appliance and itscorresponding controls, i.e. time clock, roomthermostat, etc.

3A.8 SHOWERSIf the appliance is intended for use with a shower,the shower must be thermostatically controlledand be suitable for use with a combination boiler.

3A.9 MOUNTING ON A COMBUSTIBLE SURFACEIf the appliance is to be fitted on a wall ofcombustible material, a sheet of fireproof materialmust protect the wall.

3A.10 TIMBER FRAMED BUILDINGSIf the appliance is to be fitted in a timber framedbuilding, it should be fitted in accordance with I.S.813 and local Building Regulations.The Institute of Gas Engineers publication (IGE/UP/7) ‘Guide for Gas Installations in Timber FrameBuildings’ gives specific advice on this type ofinstallation.

3A.11 INHIBITORSVokera recommend that a neutral inhibitor isused to protect the heating system from theeffects of corrosion and/or electrolytic action.Theinhibitor must be administered in strict accordancewith the manufacturers* instructions.*Fernox and Sentinel manufacture products thathave proved suitable for use with Vokeraappliances. Vokera Ltd. cannot comment on thesuitability of any other such product with ourappliances.

3A.12 DECLARATION OF CONFORMITYA Declaration of Conformity (as defined in I.S.813) must be provided on completion of theinstallation.A copy of the declaration must be given to theresponsible person and also to the gas supplier ifrequired.

9Compact

SECTION 4 INSTALLATION

4.1 DELIVERYThe appliance is delivered in a heavy-duty card-board carton. Lay the carton on the floor with thewriting the correct way up.

4.2 CONTENTSContained within the carton is:● the boiler● the wall mounting bracket● an accessories pack containing service valves

and sealing washers● the instructions pack containing installation &

servicing instructions, appliance logbook, userinstructions, guarantee registration card, 3 ampfuse and flue restrictor ring.

4.3 UNPACKINGAt the top of the carton pull both sides open – donot use a knife – unfold the rest of the carton fromaround the appliance, carefully remove allprotective packaging from the appliance, and laythe accessories etc. to one side. Protective glovesshould be used to lift the appliance, the applianceback-frame should be used for lifting points.

4.4 PREPARATION FOR MOUNTING THEAPPLIANCEThe appliance should be mounted on a smooth,non-combustible, vertical surface, which must becapable of supporting the full weight of theappliance. Care should be exercised whendetermining the position of the appliance withrespect to hidden obstructions such as pipes,cables, etc.When the position of the appliance has beendecided – using the template supplied – carefullymark the position of the wall bracket (fig. 7) andflue-hole (if applicable).

4.4.1 IMPORTANTThere are three hole types set out on theappliance template:● type 1 should be used in conjunction with

the telescopic flue kits (part no. 0225705 &0225710)

● type 2 should be used in conjunction withstandard horizontal flue kit (part no.2359029)

● type 3 should be used in conjunction withthe telescopic rear flue kits (part no.0225905 & 0225910).

4.4.2 FLUE RESTRICTOR RINGTo ensure maximum efficiency of the appliance,it may be necessary to fit one of the supplied fluerestrictor rings to the appliance flue outlet.

4.5 FITTING THE FLUEThe top flue outlet permits both horizontal andvertical flue applications to be considered,alternatively, the Vokera twin flue system can beutilised if longer flue runs are required.

4.5.1 CONCENTRIC HORIZONTAL FLUE(For concentric vertical flue, see section 4.5.2).(For twin flue applications, see section 4.5.3).

The appliance flue outlet elbow can be rotatedthrough 360º on its vertical axis. In addition theflue may be extended from the outlet elbow in thehorizontal plane (see section 4.4.2), however ifthe flue is to be extended or additional bends areto be fitted, the standard horizontal flue kit (partno. 2359029) must be used. A reduction mustalso be made to the maximum length (see table)when additional bends are used.

Bend Reduction in maximum flue length for each bend

45º bend 0.5 metre

90º bend 0.85 metre

Using the template provided (see section 4.4.1),mark and drill a 125 mm hole for the passage ofthe flue pipe. The hole should have a 1º dropfrom the boiler to outside, to eliminate thepossibility of rainwater entering the appliance viathe flue.The fixing holes for the wall-mounting bracketshould now be drilled and plugged, an appropriatetype and quantity of fixing should be used toensure that the bracket is mounted securely.Once the bracket has been secured to the wall,mount the appliance onto the bracket.

Horizontal flue terminals and accessories

Part No. Description Min-Max Length

0225705 Standard telescopic flue 380 mm – 600 mm(Dimension ‘X’)

0225710 Extended telescopic flue 600 mm – 920 mm(Dimension ‘X’)

2359029 Horizontal flue kitFor use with add. Bends 833 mm& extensions (dimension ‘X’)

2359069 750 mm extension 750 mm2359079 1500 mm extension 1500 mm2359049 45º bend (pair) N/A2359059 90º bend N/A0225760 Wall bracket (5) N/A

Total flue length Restrictor required

Less than 0.85 metreLess than 2 metreLess than 3 metreLess than 4.25 metre

42 mm diameter44 mm diameter46 mm diameterNot installed

Compact 24

Compact 28

Total flue length Restrictor required

Less than 0.85 metreLess than 1.70 metreLess than 2.70 metreLess than 3.40 metre

45 mm diameter47 mm diameter49 mm diameterNot installed

10 Compact

Carefully measure the distance from the centre ofthe appliance flue outlet to the face of the outsidewall (dimension ‘X’, fig. 8). Add 50 mm todimension ‘X’ to give the overall flue length(dimension ‘Y’). Using the complete telescopicflue assembly adjust the length to suit dimension‘Y’. Once the telescopic flue terminal has beenadjusted to the correct length, secure the flueassembly with the screw supplied.Insert the flue restrictor ring (supplied in theinstruction pack) into the appliance flue gas outlet.Slide the flue assembly into the previously drilledflue hole and locate the flue bend over theappliance flue outlet. Push the flue bend downover the appliance flue outlet and ensure thecorrect seal is made. Pull the flue assemblytowards and over the flue bend – using a twistingaction – ensuring the correct seal is made. Checkthat the terminal protrudes past the finishedoutside wall by the correct length (115 mm).

NOTEYou must ensure that the entire flue system isproperly supported and connected. Seal the flueassembly to the wall using cement or a suitablealternative that will provide satisfactoryweatherproofing. The interior and exterior trimcan now be fitted.

FITTING THE STANDARD (2359029)HORIZONTAL FLUE KIT (see section 4.4.1)Carefully measure the distance from the centreof the appliance flue outlet to the face of theoutside wall (dimension ‘X’, fig. 8A). Ensure theinner (60 mm) pipe is fully inserted into the outer(100 mm) pipe (when the inner pipe is fullyinserted, it stands proud of the outer pipe by 7.5mm). Add 32 mm to dimension ‘X’ to give theoverall flue length (dimension ‘Y’). The standardhorizontal flue kit (part no. 2359029) is suitablefor a distance (dimension ‘Y’) of up to 865 mm.NOTEDimension ‘Y’ is measured from the end of theterminal to the end of the outer (100 mm) pipe.The internal trim should be fitted to the flue pipebefore connection of the 90º bend.Insert the flue restrictor ring (supplied withinstruction pack) into the appliance flue gas outletif the total flue length is less than 1.0 metre.If the horizontal flue kit (2359029) requires to becut to the correct size (dimension ‘Y’), you mustensure that the inner (60 mm) pipe stands proudof the outer (100 mm) pipe by 7.5 mm (fig. 8B).Ensure any burrs are filed or removed and thatany seals are located properly before assembly.Connect the inner (60 mm) pipe of the terminalassembly to the push-fit end of the 90º bend(supplied) using a twisting action. Insert theassembled flue into the previously drilled hole.Using the clips & screws supplied, connect theflue assembly to the boiler, ensuring that theterminal protrudes past the finished outside wallby the correct length (135 mm).You must ensure that the entire flue system isproperly supported and connected.Seal the flue assembly to the wall using cementor a suitable alternative that will providesatisfactory weatherproofing. The exterior trimcan now be fitted.

EXTENDING THE HORIZONTAL FLUEIf the horizontal flue requires extension/s oradditional bend/s, the standard horizontal flueterminal (2359029) must be used. Connect thebend – supplied with the terminal kit – to the topof the boiler using the clips, screws & gasketssupplied. The additional bends & extensions havean internal push-fit connection, care should betaken to ensure that the correct seal is madewhen assembling the flue system. Connect therequired number of flue extensions or bends (upto the maximum equivalent flue length) to the flueterminal using the clips, screws & gaskets supplied(fig. 8A & 8B).

type 1= centre of rear flue holeusing only 0225705 or0225710 flue

type 2= centre of rear flue holefor use with 2359029

type 3= for rear flue only

Fig. 8“X” + 50 mm = “Y”

115 mm Fig. 8A

Dimension “Y”

Dimension “X”

Max 833 mm

135 mm7,5

110

Fig. 7

Total flue length Restrictor required

Less than 1 metreCompact 24 Compact 28

40 mm diameter 42 mm diameter

FITTING THE TELESCOPIC FLUE KIT(0225705 & 0225710)

3

2

1

11Compact

Fig. 9

465 mm

300 mmmin.

150 mm

NOTEWhen cutting the horizontal flue terminal or anextension to the required length, you must ensurethat the excess is cut from the plain end of theterminal or extension, and that the inner (60 mm)pipe is 7.5 mm longer than outer (100 mm) pipe(fig. 8A & 8B). Remove any burrs, and check thatany seals are located properly.You must ensure that the entire flue system isproperly supported and connected.Seal the flue assembly to the wall using cementor a suitable alternative that will providesatisfactory weatherproofing. The interior andexterior trim can now be fitted.

4.5.2 CONCENTRIC VERTICAL FLUE

The vertical flue terminal can be connected directlyto the appliance flue outlet. Alternatively, anextension or bend can be connected to theappliance flue outlet if desired (see section 4.4.2),however if additional bends are fitted, a reductionmust be made to the maximum flue length (seetable below).

Using the dimensions given in fig. 9 as a reference,mark and cut a 105 mm hole in the ceiling and/or roof.

Fig. 8BBoiler

Push-fit connection

Extension

7,5 mm

Fit the appropriate flashing plate to the roof andinsert the vertical flue terminal through the flashingplate from the outside, ensuring that the collar onthe flue terminal fits over the flashing.The fixing holes for the wall-mounting bracketshould now be drilled and plugged, an appropriatetype and quantity of fixing should be used toensure that the bracket is mounted securely.Once the bracket has been secured to the wall,mount the appliance onto the bracket.IMPORTANTThe vertical flue terminal is 1.0 metre in lengthand cannot be cut; therefore it may be necessaryto adjust the height of the appliance to suit or usea suitable extension.Insert the flue restrictor ring into the appliance flueoutlet, in accordance with the table in section 4.4.2.Connect the vertical flue assembly to the boilerflue spigot using the 60 mm & 100 mm clips,gaskets, & screws (supplied), ensuring the correctseal is made. The flue support bracket (suppliedwith the vertical flue kit) can now be fitted.If the vertical flue requires extension/s or additionalbend/s, connect the required number of flueextensions or bends (up to the maximumequivalent flue length) between the boiler andvertical flue assembly (fig. 8B).NOTEWhen cutting an extension to the required length,you must ensure that the excess is cut from theplain end of the extension and that the inner (60mm) pipe is 7.5 mm longer than outer (100 mm)pipe (fig. 8B). Remove any burrs, and check thatany seals are located properly.You must ensure that the entire flue system isproperly supported and connected.

Total flue length Restrictor required

Less than 1.5 metreLess than 2.5 metreLess than 3.5 metreLess than 5 metre

42 mm diameter44 mm diameter46 mm diameterNot installed

Compact 24

Compact 28

Total flue length Restrictor required

Less than 1.5 metreLess than 2.4 metreLess than 3.4 metreLess than 4.2 metre

45 mm diameter47 mm diameter49 mm diameterNot installed

4.5.3 TWIN FLUE SYSTEM

Compact 24

Total flue length (air = fumes) Restrictor required

Less than 4.5 + 4.5Less than 10.5 + 10.5Less than 14 + 14

42 mm diameter44 mm diameter46 mm diameter

Bend Reduction in maximum flue length for each bend

45º bend 0.5 metre

90º bend 0.85 metre

Part No. Description Length

2359039 Vertical flue terminal 1.0 metre0225770 Pitched roof flashing plate N/A0225765 Flat roof flashing plate N/A2359069 750 mm extension 750 mm2359079 1500 mm extension 1500 mm2359049 45º bend (pair) N/A2359059 90º bend N/A0225760 Wall bracket (5) N/A

Vertical flue terminal and accessories

12 Compact

4.5.3.2 INSTALLATION OF CONDENSATE DRAIN KIT(fig. 10B)The condensate drain kit must be fitted within 1 metreof the appliance flue outlet. It is recommended thatthe condensate drain kit should be fitted in the verticalplane, however it can be fitted horizontally with care.● Fit the first bend to the condensate drain kit or

exhaust connection manifold by firmly pushingin to position.

● Using the two holes in the exhaust connectionmanifold as a guide, drill a 3 mm hole in eachand secure using the screws provided.

● Connect the air inlet pipe to the air baffle as above.● The twin flue pipes extensions and accessories

can now be installed by pushing together (theplain end of each extension or bend should bepushed approximately 50 mm into the femalesocket of the previous piece).The condensate drain trap must be connectedto the drain in accordance with buildingRegulations or other rules in force.

Compact 28

Total flue length Restrictor required

Less than 4 + 4Less than 8 + 8Less than 12.5 + 12.5Less than 14 + 14

45 mm diameter47 mm diameter49 mm diameterNot required

The Vokera twin flue system enables greater fluedistances to be achieved (see section 2.8) thanthat of the standard concentric flue system. It canbe used for horizontal or vertical applications,however the twin flue system must be convertedto the dedicated concentric flue kit for termination.It is essential that the installation of the twin fluesystem be carried out in strict accordance withthese instructions.

GUIDANCE NOTES ON TWIN FLUEINSTALLATION● The flue must have a fall back of 1º back to the

appliance to allow any condensate that formsin the flue system to drain. Consideration mustalso be given to the fact that there is thepossibility of a small amount of condensatedripping from the terminal.

● Ensure that the entire flue system is adequatelysupported, use at least one bracket for eachextension.

● Extreme care must be taken to ensure that nodebris is allowed to enter the flue system atany time.

● As the exhaust outlet pipe can reach very hightemperatures it must be protected to preventpersons touching the hot surface.

Twin flue accessoriesPart No. Description Length0225805 Horizontal flue terminal 1.0 metre0225810 Vertical flue terminal 1.0 metre300 Twin adapter kit for Compact 24 N/A2359249 Twin adapter kit for Compact 28 N/A0225770 Pitched roof flashing plate N/A0225765 Flat roof flashing plate N/A0225815 Condensate drain kit N/A0225820 0.25 m extension (pair) 250 mm0225825 0.5 m extension (pair) 500 mm0225830 1.0 m extension (pair) 1000 mm0225835 2.0 m extension (pair) 2000 mm0225840 45º bend (pair) N/A0225845 90º bend (pair) N/A0225850 Twin bracket (5) N/A0225855 Single bracket (5) N/A

MOUNTING THE BOILERThe fixing holes for the wall-mounting bracketshould now be drilled and plugged, anappropriate type and quantity of fixing should beused to ensure that the bracket is mountedsecurely. Once the bracket has been secured tothe wall, mount the appliance onto the bracket.

4.5.3.1 INSTALLATION OF TWIN ADAPTOR KIT (fig. 10 &10A)● Insert the exhaust connection manifold (B) onto

the appliance flue outlet and secure to the fluespigot using the screws provided.

● Insert the silicone seal into the exhaust outlet.● Remove the blanking plates (located to the left

of the appliance flue outlet) and – using thesame screws – install the air baffle (A).

Fig. 10

Fig. 10A

Condensate drain kit

restrictor ring

restrictor ring

flue outlet

flue outlet

air inlet

air inlet

Compact 24

Compact 28

Fig. 10B

13Compact

4.5.3.3 HORIZONTAL TERMINATION (fig. 11)The twin flue system must be converted to thededicated concentric flue kit for termination.● The horizontal terminal is supplied with a built-

in converter box and cannot be shortened.● A 130 mm hole is required for the passage of

the concentric terminal through the wall.Depending on site conditions it may be preferableto install the terminal assembly prior to fitting thetwin flue pipes.Mark and drill a 130 mm hole for the passage ofthe horizontal flue terminal, ensuring that there isa 1º fall back to the boiler (17 mm per 1000 mm).Insert the terminal assembly into the flue hole.Push-fit the twin flue pipes onto the concentric totwin converter box ensuring that the exhaust pipeconnects to the exhaust connection on theconcentric to twin converter.If necessary cut the plain ends (male) of the twinflue pipes to allow connection to the concentricto twin converter.NOTEBefore cutting twin flue pipes ensure allowanceshave been made for connection onto the previouspiece and onto the concentric to twin converter.The last twin flue pipes must be pushed 50mmonto the male sockets of the concentric to twinconverter.

NOTEYou must ensure that the entire flue system isproperly supported and connected.

When cutting an extension to the required length,you should ensure that the excess is cut fromthe plain end of the extension. Remove any burrs,and check that both seals are located properly.Seal the flue terminal assembly to the wall usingcement or a suitable alternative that will providesatisfactory weatherproofing. The interior andexterior trim can now be fitted.

4.5.3.4 VERTICAL TERMINATION (fig. 12)The twin flue system must be converted to thededicated concentric flue kit for termination.● The vertical terminal is supplied with a built-in

converter box and cannot be shortened.● A 130 mm hole is required for the passage of

the concentric terminal through the ceiling and/or roof.

Depending on site conditions it may be preferableto install the terminal assembly prior to fitting thetwin flue pipes.Fit the appropriate flashing plate to the roof andinsert the vertical flue terminal through theflashing plate from the outside, ensuring that thecollar on the flue terminal fits over the flashing.Push-fit the twin flue pipes onto the concentric totwin converter ensuring that the exhaust pipe

connects to the exhaust connection on theconcentric to twin converter.If necessary cut the plain ends (male) of the twinflue pipes to allow connection to the concentricto twin converter.NOTE• Before cutting twin flue pipes ensure

allowances have been made for connectiononto the previous piece and onto the concentricto twin converter. The last twin flue pipes mustbe pushed 50 mm onto the male spigots of theconcentric to twin converter.

• You must ensure that the entire flue system isproperly supported and connected.

• Ensure that any horizontal sections of pipehave a 1º fall towards the appliance (17 mmper 1000 mm).

• The convertor box on the vertical terminal willhave to be temporarily removed when insertingthe terminal through the flashing.

• The condensate trap must be primed with waterprior to commissioning the boiler.

convertor box

condensate trap

Fig. 11

Fig. 12

condensate trap

convertor box

4.6 CONNECTING THE GAS AND WATERThe appliance is supplied with an accessoriespack that contains large and small sealing wash-ers, service valves, and pipe connections.The service valves are of the compression type,the pipe connections have plain copper ends.When connecting pipework to the valves or con-nections, tighten the compression end first, theninsert the sealing washers before tightening thevalve or connection to the appliance. It will benecessary to hold the valve or connection withone spanner whilst tightening with another.

4.6.1 GAS (fig. 6)The appliance is supplied with a 15 mm servicevalve, connect a 15 mm pipe to the inlet of thevalve, and tighten both nuts.NOTEIt will be necessary to calculate the diameter ofthe gas pipe to ensure the appliance has anadequate supply of gas.

14 Compact

4.6.2 FLOW & RETURN (fig. 6)The appliance is supplied with 22 mm servicevalves for the heating connections, connect 22 mmpipe to the inlet of each valve and tighten both nuts.

4.6.3 SAFETY VALVE (fig. 6)The appliance is supplied with a 15 mm compres-sion coupling. Connect a 15 mm pipe to thecoupling and tighten. It may be necessary to fit anon-return valve if the installation is subject tomains knock, in order to eliminate false activationof the domestic hot water flow switch.

4.6.4 COLD WATER INLET (fig. 6)The appliance is supplied with a 15mm stopcock,connect a 15mm service pipe to the inlet of theservice valve and tighten both nuts. It may benecessary to fit a pressure reducing valve if theinstallation is subject high-pressure fluctuationsor high pressure surges.

4.6.5 HOT WATER OUTLET (fig. 6)The appliance is supplied with a 15 mm coppertail, connect a 15 mm pipe and suitable couplingto the tail and tighten. The discharge pipe musthave a continuos fall away from the boiler tooutside and allow any water to drain away therebyeliminating the possibility of freezing. The dis-charge pipe must terminate in a position whereany water – possibly boiling – discharges safelywithout causing damage or injury, but is stillvisible.

4.7 ELECTRICAL CONNECTIONSThe electrical supply must be as specified in 3.7/3.7A. the appliance is supplied, pre-wired with a1.0 metre length of flex, connect the wires asfollows:● connect the Brown wire to the L (Live) terminal

of the plug or fused isolator● connect the Blue wire to the N (Neutral) terminal

of the plug or fused isolator● connect the Green/Yellow wire to the E (Earth)

terminal of the plug or isolator● ensure the plug or fused isolator is fitted with a

3 amp fuse.If this method of connection is unsuitable, pleaserefer to section 8. A qualified electrician shouldconnect the electrical supply to the appliance.The electrical supply must be as specified insection 3.7/3.7A. A qualified electrician shouldconnect the electrical supply to the appliance. Ifcontrols – external to the appliance – are required,a competent person must undertake the designof any external electrical circuits, please refer tosection 8 for detailed instructions. ANYEXTERNAL CONTROL OR WIRING MUST BESERVED FROM THE SAME ISOLATOR ASTHAT OF THE APPLIANCE. The supply cablefrom the isolator to the appliance must be 3-coreflexible sized 0.75mm to BS 6500. Wiring to theappliance must be rated for operation in contactwith surfaces up to 90 ºC.

4.7.1 CASING REMOVALTo gain access to the appliance electricalconnections you must first remove the casing,proceed as follows:● Locate and remove the 3 screws that secure

the outer casing to the appliance (fig 13).● Gently pull one side of the casing then the other

to disengage it from the retaining clips.● Lift the casing upward to disengage it from the

top locating hooks and then remove.● Store the casing and screws safely until

required. Re-fit in the reverse order.

4.7.2 ELECTRICAL CONNECTIONThe appliance terminal strip is located behind thecontrol fascia (fig. 14).NOTEIf it is anticipated that external controls will berequired please refer to the wiring diagrams insection 8 for more detailed information.

Control panel screws and casing screws

Fig. 13

Fig. 14

15Compact

4.7.3 CONNECTING THE MAINS (230V) INPUT (fig.14)The appliance comes with a factory fitted mainelectrical supply cable. If it’s necessary to changethe main electrical cable, proceed as follow.Open the terminal strip cover. Pass the cablethrough the cable anchorage. Connect the supplycable wires (earth, live, and neutral) to theircorresponding terminals on the terminal strip.Ensure that the EARTH wire is left slightly longerthat the others, this will prevent strain on theEARTH wire should the cable become taut.The securing screw on the cable anchorageshould now be tightened. This must be donebefore the control fascia is re-fitted in the uprightposition. The terminal strip cover can now be re-fitted.

16 Compact

5.1 GAS SUPPLY INSTALLATIONInspect the entire installation including the gasmeter, test for soundness and purge.

5.2 THE HEATING SYSTEMThe appliance contains components that maybecome damaged or rendered inoperable by oilsand/or debris that are residual from the installa-tion of the system, consequently it is essentialthat the appliance is flushed in accordance withthe following instructions.

5.3 INITIAL FILLING OF THE SYSTEMEnsure both flow and return service valves areopen, remove appliance casing as described insection 4.7.1, identify the automatic air releasevalve, and loosen the dust cap by turning capanti-clockwise one full turn. IMPORTANT, THEREARE NO MANUAL AIR RELEASE VALVESLOCATED ON THE APPLIANCE. Ensure allmanual air release valves located on the heatingsystem are closed. Using the method of filling asdescribed in fig. 5, slowly proceed to fill thesystem, as water enters the system the pressuregauge will begin to rise, once the gauge hasreached 1 bar close the filling valve and beginventing all manual air release valves, starting atthe lowest first. It may be necessary to go backand top-up the pressure until the entire systemhas been filled. Inspect the system for watersoundness, rectifying any leaks.

5.4 INITIAL FLUSHINGThe whole of the heating system must be flushedboth cold and hot as detailed in section 5.9. openall radiator or heating valves and the appliancecentral heating valves. Drain the boiler and sys-tem from the lowest points. Open the drain valvefull bore to remove any installation debris fromthe boiler prior to lighting. Refill the boiler andheating system as described in section 5.3.

5.5 FILLING THE HOT WATER SYSTEMClose all hot water outlets, turn appliance stop-cock on (anti-clockwise), slowly open each outletuntil all air has been expelled and clear water isdischarged. Check pipe-work etc. for water sound-ness.

5.6 PRE-OPERATION CHECKSBefore attempting the initial lighting of the appliance,the following checks must be carried out:● Ensure all gas service valves from the meter to

the appliance are open and the supply pipe hasbeen properly purged.

SECTION 5 COMMISSIONING

● Ensure the proper electrical checks have beencarried out (section 7.11), particularly continuity,polarity and resistance to earth.

● Ensure the 3-amp fuse – supplied with theappliance – has been fitted.

● Ensure the system has been filled, aired, andthe pressure set to 1bar.

● Ensure the flue has been fitted properly and inaccordance with the instructions.

● Ensure all appliance service valves are open.

5.7 INITIAL LIGHTINGEnsure the electrical supply to the appliance isswitched on. Switch the time clock or programmerto an ‘on’ position and ensure all external controlsare also calling for heat.The appliance will now operate in as described insection 1.2. Should the appliance fail to ignite,refer to section 5.6 and/or section 7 (fault finding).

5.8 CHECKING BURNER PRESSURESAlthough burner pressures are set at the factory,it is necessary to check them during thecommissioning procedure. Isolate the appliancefrom the electrical supply and remove the casingas described in section 4.7.1.After attaching a manometer to the outlet testpoint of the gas valve (fig. 23), restore the electricalsupply to the appliance, turn the selector to hotwater only (summer position), and rotate theDHW temperature selector to maximum.

Maximum burner pressureFully open a hot water outlet – preferably the bathtap – and check that reading on the manometercorresponds to the data given in section 2.3.

Minimum burner pressureAfter checking the maximum burner pressure,remove one of the black wires from themodulating coil on the gas valve. The burnerpressure will drop to the minimum setting. Checkthat the reading on the manometer correspondswith the data given in section 2.3.Once the gas pressures have been checked:● isolate the appliance from the electrical supply● close the hot water outlet● remove the manometer from the outlet test

point and tighten the test point screw● refit the appliance casing.Should either the maximum or minimum burnerpressure require to be adjusted, refer to section7.6 for the correct adjustment procedure.

Fig. 15

Gas pressure adjustmentprotective cover

Maximum pressureadjustment screw (a)

Minimum pressure ad-justment screw (b)

17Compact

5.9 FINAL FLUSHING OF THE HEATING SYSTEMThe system shall be flushed in accordance withBS 7593. If a cleanser is to be used, it shall befrom a reputable manufacturer* and shall beadministered in strict accordance with themanufacturers instructions.*Both Sentinel and Fernox manufacture productsthat have proved suitable for use with Vokeraappliances. Vokera Ltd. cannot comment on thesuitability of any other such product with ourappliances.

5.9.1 INHIBITORSSee section 3 “General requirements”.

5.10 SETTING THE FLOW TEMPERATUREThe heating flow temperature selector can beadjusted from a minimum of 40 °C, to a maximumof 82 °C. In addition, when the selector is rotatedto the Auto position, the appliance willautomatically adjust the outlet flow temperatureto compensate for inclement weather

*When the selector is left within this range, the appliance willautomatically raise the outlet temperature during cold orinclement weather conditions

5.11 SETTING THE SYSTEM DESIGN PRESSUREThe design pressure should be I minimum of 1bar and a maximum of 1.5 bar.The actual reading should ideally be 1 bar plusthe equivalent height in metres to the highestpoint in the system above the base of the appli-ance. (Up to the maximum of 1.5 bar total).N.B. The safety valve is set to lift at 3 bar/ 30m/45psig.To lower the system pressure to the requiredvalue, pull lever on head of safety valve to releasewater until the required figure registers on thepressure gauge (fig.1).

5.12 REGULATING THE CENTRAL HEATING SYS-TEMFully open all radiator and circuit valves and runthe appliance in the central heating mode untilheated water is circulating. If conditions are warmremove any thermostatic valve heads. Adjustradiator return valves and any branch circuitreturn valves until the individual returntemperatures are correct and are approximatelyequal.

5.13 REGULATING THE DOMESTIC HOT WATERThe appliance is supplied with a built-in flowrestrictor that limits the amount of water passingthrough the heat exchanger, thereby ensuring areasonable temperature at the outlet.The outlet temperature can also be adjusted viathe DHW temperature selector.If the required outlet temperature cannot beobtained by rotating the DHW temperatureselector to its maximum setting, the adjustable

stopcock should be used to limit the availableflow rate at the outlet. Slowly turn the adjustablestopcock clockwise until a satisfactorytemperature is obtained.Please note that it’s prudent to set the domestichot water outlet temperature at the lowestacceptable temperature, as higher temperaturescan be realised by reducing the flow rate at theindividual hot water outlets.

NOTEThe appliance will light to provide hot water whenthe domestic hot water flow switch senses a flowrate of 2.0 litres –per minute – or more.

5.14 FINAL CHECKS● ENSURE ALL TEST NIPPLES ON THE

APPLIANCE GAS VALVE ARE TIGHT ANDHAVE BEEN CHECKED FOR SOUNDNESS.

● ENSURE THE APPLIANCE FLUE SYSTEM ISFITTED CORRECTLY AND IS PROPERLYSECURED.

● ENSURE ALL PIPE WORK IS RE-CHECKEDFOR SOUNDNESS.

● RE-FIT APPLIANCE CASING.● COMPLETE APPLIANCE LOGBOOK.

Complete details of the boiler, controls, installation,and commissioning in the logbook supplied withthe boiler. This is an important document, whichmust be correctly completed and handed to theuser. Failure to install and commission theappliance to the manufacturers instructions mayinvalidate the warranty.

5.15 INSTRUCTING THE USERHand over all documentation supplied with thisappliance – including these instructions – andexplain the importance of keeping them in a safeplace.Explain to the user how to isolate the appliancefrom the gas, water, and electricity supplies, andthe locations of all drain points.Show the user how to operate the appliance andShow the user the position of the filling valve andhow to top-up the system pressure correctly, andshow the location of all manual air release points.Explain to the user how to turn off the appliancefor both long and short periods, and advise on thenecessary precautions to prevent frost damage.Explain to the user that for continued safe andefficient operation, the appliance must be servicedannually by a competent person.

Sector Range

Low sectorAuto sectorHigh sector

40° - 50°C55° - 65°C*65° - 82°C

Flow temperature selection

18 Compact

SECTION 6 SERVICING INSTRUCTIONS

6.1 GENERALTo ensure the continued safe and efficientoperation of the appliance, it is recommendedthat it is checked and serviced at regular intervals.

The frequency of servicing will depend upon theparticular installation conditions, but in general,once per year should be adequate.

It is the law that any servicing work is carried outby competent person such as a Vokera engineer,an approved service agent, British Gas, or otherCORGI registered personnel.

The following instructions apply to the applianceand its controls, but it should be rememberedthat the central heating system will also requireattention from time to time.

Always use genuine Vokera spare parts

6.2 ROUTINE ANNUAL SERVICINGCheck the operation of the appliance in both ‘hotwater only’ and ‘heating and hot water’ modes.Ensure the appliance functions as described insection 7. Compare the performance of the appli-ance with its design specification. The cause ofany noticeable deterioration should be identifiedand rectified without delay.Thoroughly inspect the appliance for signs ofdamage or deterioration especially the flue sys-tem and the electrical apparatus.Check and adjust – if necessary – all burnerpressure settings (see section 7.6).Check and adjust – if necessary – the systemdesign pressure (see section 5.11).Carry out an analysis of the flue gases (seesection 7.7), and visually check the condition ofthe entire flue assembly. Compare the resultswith the appliance design specification. Anydeterioration in performance must be identifiedand rectified without delay.Ensure both flue venturis are clean and free fromany debris or obstruction.Ensure both the burner and heat exchanger areclean and free from any debris or obstruction.Inspect all joints for signs of leakage and repair ifnecessary.Refer to the commissioning section and/or re-placement of parts section for detailed instructionif required.

6.3 REPLACEMENT OF COMPONENTSAlthough it is anticipated that this appliance willgive years of reliable, trouble free service, the lifespan of components will be determined by fac-tors such as operating conditions and usage.Should the appliance develop a fault, the faultfinding section will assist in determining whichcomponent is malfunctioning.

6.4 MAIN HEAT EXCHANGER (de-scaling)The main heat exchanger may – when operatingunder certain conditions – become affected byscaling. Evidence of this will be a deterioration of

the hot water performance. The heat exchangercan be de-scaled using a proprietary de-scalantwithout having to remove it from the appliance.However the appliance must be disconnectedfrom the hot and cold service pipes, the de-scalant should be administered with strict adher-ence to the manufacturers instructions. Re-connect the hot and cold services only afterthorough flushing with clean water has takenplace.

6.5 COMPONENT REMOVAL PROCEDURETo remove a component, access to the interior ofthe appliance is essential. Isolate the appliancefrom the electrical supply and remove the fuse.And when necessary, close all service valves onthe appliance, remove the appliance casing asdescribed in section 4.7.1, drain the primarywater content from the appliance via the safetyvalve, and drain off secondary water content fromthe appliance via a hot water outlet. Ensure somewater absorbent cloths are available to catch anyresidual water that may drip from the appliance orremoved component. Undertake a completecommissioning check as detailed in section 5,after replacing any component. ALWAYS TESTFOR GAS SOUNDNESS IF ANY GAS CARRY-ING COMPONENTS HAVE BEEN REMOVEDOR DISTURBED.

6.6 PUMP HEAD fig. 16Carry out component removal procedure as de-scribed in section 6.5.Using a 4 mm Allen key or ‘T’ bar, unscrew andremove the four Allen screws that hold the pumpin position, pull firmly on the pump head to releaseit from the base. Disconnect the electrical leads.Replace in the reverse order.

6.7 SAFETY VALVE fig. 16Carry out component removal procedure as de-scribed in 6.5.Disconnect the outlet pipe from the safety valve,unscrew and remove the hex bush from thesafety valve outlet, remove safety valve lockingpin from appliance manifold. Replace in thereverse order

Fig. 16

Pump

Safety valve

19Compact

Fig. 19

Fig. 20

6.8 AUTOMATIC AIR RELEASE VALVE (AAV, fig.17)Carry out component removal procedure as de-scribed in 6.5.Remove the locking pins at the pump outlet, andthe flow & return connection of the heat ex-changer, disconnect both pipes from the heatexchanger, and remove the return pipe from thepump outlet. Remove the locking pin and expan-sion pipe from the pump base. Using a suitablepair of pliers, unscrew the AAV from the pumpbase. Replace in the reverse order.

6.9 WATER PRESSURE SWITCH fig. 18Carry out component removal procedure as de-scribed in 6.5.Remove locking pin from heating flow pipe at theheating manifold and withdraw the pipe from themanifold. Remove locking pin and the waterpressure switch from the heating manifold, pullback protective cover – and after taking note ofthe electrical connections – disconnect the wir-ing. Replace in the reverse order.

6.10 DOMESTIC WATER FLOW SWITCH fig. 19Carry out component removal procedure as de-scribed in 6.5.Remove black electrical plug from the domesticwater flow switch, disconnect and remove inletpipe between the domestic water flow switch andthe heat exchanger, remove locking pin from thedomestic water flow switch, the switch can nowbe removed from the appliance. Replace in thereverse order.

Fig. 17

AAV

Fig. 18

WATER PRESSURESWITCH

6.11 PRESSURE GAUGE (fig. 1)Carry out component removal procedure as de-scribed in 6.5.Remove pressure gauge locking pin, located onpump base, and withdraw the pressure gaugepipe, locate the spring tabs on the pressuregauge body, push and hold tabs in, to enableextraction of the gauge from its location. Replacein the reverse order.

6.12 PRIMARY AND SECONDARY THERMISTORS(fig. 20-21)Carry out component removal procedure as de-scribed in 6.5.Pull back protective rubber cover from the ther-mistor, disconnect thermistor electrical plug, us-ing a 13 mm spanner slacken and remove thethermistor and sealing washer. Replace in thereverse order.

6.13 HIGH LIMIT THERMOSTAT fig. 20Carry out component removal procedure as de-scribed in 6.5.Pull off electrical plug from the high limit thermo-stat, slacken and remove retaining screws.Replace in reverse order.

primary thermistor

high limit thermostat

Fig. 21

secondary thermistor

20 Compact

6.14 PRINTED CIRCUIT BOARD (PCB, fig. 22)Carry out component removal procedure as de-scribed in section 6.5.Remove the PCB cover, after carefully takingnote off all wiring connections, disconnect allwiring from the PCB, locate and remove the PCBsecuring screws, remove PCB. Replace in thereverse order.

6.15 INTEGRAL TIME SWITCH (fig. 22A)Carry out component removal procedure as de-scribed in 6.5.Remove the PCB cover, locate and remove thetime clock retaining screws, remove time clockafter carefully taking note off all wiring connec-tions. Replace in the reverse order.

6.16 GAS VALVE fig. 23Carry out component removal procedure as de-scribed in section 6.5.The gas valve must be changed as complete unit.Disconnect both electrical plugs from the gasvalve, disconnect silicone tube from gas valveregulator, slacken and unscrew gas valve inletand outlet connections, please note, the sealingwashers must be discarded and replaced withnew sealing washers, locate and remove gasvalve retaining screws on the underside of theboiler, the gas valve can now be removed. Replacein the reverse order. Check and adjust burnerpressure settings. WARNING, A GAS SOUND-NESS CHECK MUST BE CARRIED OUT.

Fig. 22

6.17 BURNER, INJECTORS AND SPARK/SENSEELECTRODE (fig. 24 & 25)Carry out component removal procedure as de-scribed in 6.5.Remove outer combustion cover by un-clippingthe two retaining clips located at the base of thecombustion cover, gently pull the cover towardsyou before lifting and disengaging it from the topretaining lugs. Locate and remove the two screwsat the base of the inner combustion cover, pull thecover towards you before lifting and disengagingit from the top retaining lugs.Disconnect both the electrode lead from its con-nector at the top of the control fascia, and theelectrode earth lead from the spade connector onthe appliance frame. Locate and remove the fourscrews which secure the burner in position, gen-tly ease the burner out of its location whilst alsoeasing the electrode sealing grommet from itslocation.Once the burner has been removed, locate theburner injectors – located to the rear of thecombustion chamber – and remove. Replace inthe reverse order. Please note, the injector sealingwashers must be replaced if the injectors havebeen removed, ensure all seals are in goodcondition, taking care to ensure they are replacedcorrectly.

Fig. 22A

Fig. 24

M

M

CLK-1

CLK-4

Fig. 23

21Compact

Fig. 26

Fig. 27

6.18 FLUE FAN (fig. 24 & 28)Carry out component removal procedure as de-scribed in section 6.5.Remove outer combustion cover by un-clippingthe two retaining clips located at the base of thecombustion cover, gently pull the cover towardsyou before lifting and disengaging it from the topretaining lugs. Disconnect the electrical connec-tions and silicone tubes attached to the fan,noting their positions. Locate and remove thecombustion test point screws and the cross headscrew which retains the combustion analysis testpoint assembly, push the test point into the fanhousing, locate and remove the three screwswhich secure the fan to the flue hood, ease thefan from its location. Replace in the reverseorder. Ensure all seals are in good condition,taking care to ensure they are replaced correctly.

Fig. 25

6.19 HEAT EXCHANGER fig. 24 & 26Carry out component removal procedure as de-scribed in 6.5. Remove outer combustion coverby un-clipping the two retaining clips located atthe base of the combustion cover, gently pull thecover towards you before lifting and disengagingit from the top retaining lugs. Locate and removethe two screws at the base of the inner combustioncover, pull the cover towards you before liftingand disengaging it from the top retaining lugs.Remove locking pins and disconnect the hoses,from the flow and return connections on the heatexchanger. Disconnect the hot and cold connec-tions on the heat exchanger. Disconnect theelectrical plugs from the primary thermistor andhigh limit thermostat at the heat exchanger, theheat exchanger can now be withdrawn from theappliance. Replace in the reverse order. Ensureall seals are in good condition, taking care toensure they are replaced correctly.

6.20 AIR PRESSURE SWITCH (fig. 1, 24 & 28)Carry out component removal procedure as de-scribed in section 6.5.Remove outer combustion cover by un-clipping thetwo retaining clips located at the base of thecombustion cover, gently pull the cover towardsyou before lifting and disengaging it from the topretaining lugs. Locate and remove the two screwsholding the air pressure switch to the combustionchamber. Disconnect the electrical connectionsand silicone tubes attached to the air pressureswitch, noting their positions. Take-away the wiresbelt. Replace in the reverse order. Replace with anew belt. Ensure all seals are in good condition,taking care to ensure they are replaced correctly.

6.21 EXPANSION VESSELDue to the compact design of this appliance,removal and/or replacement of the expansionvessel requires the appliance to be removed fromthe wall, if this is deemed impractical, an externalexpansion vessel may be fitted to the return pipeas close to the appliance as possible.

6.22 EXPANSION VESSEL (removal) fig. 1Carry out component removal procedure as de-scribed in 6.5.Isolate gas, water and electrical supplies from theappliance. Disconnect and remove the electricalsupply cable from the appliance. Disconnect allservice valves and connections from the appli-ance. Disconnect the flue from the appliance.The appliance can now be lifted from its mountingbracket. Lay the appliance on its side and discon-nect the expansion pipe from the vessel, slackenand remove the locknut that secures the lowerpart of the vessel to the appliance frame. Locateand remove the six screws that secure the vesseltop holding plate, remove the plate. The expan-sion vessel can now be removed. Replace in thereverse order. Ensure all seals are in good con-dition, taking care to ensure they are replacedcorrectly. GAS AND WATER SOUNDNESSCHECKS MUST BE CARRIED OUT.

Fig. 28

22 Compact

7.1 CHECKING APPLIANCE OPERATIONWhen carrying out any repairs or servicing to theappliance the relevant commissioning proceduremust be undertaken to ensure the continued safeoperation of the appliance. Particular attentionshould be made to ensure gas soundness, watersoundness, and the electrical integrity of theappliance.

7.2 AT REST MODEWhen the appliance is at rest, (no demand forheat or water) the green LED will be illuminatedto indicate there are no faults, if the appliance hasbeen inactive for aproximately 24 hours, it willenergise the pump for a short period to ensurethe pump does not seize due to inactivity. Theappliance also has built-in frost protection, whichwill operate even if the mode selector switch is inthe ‘off’ position.

7.3 HOT WATER MODEOpening a hot water outlet and enabling a flowrate of 2 litres or more, causes the domestic waterflow switch to activate. Activation of the domestichot water flow switch allows the fan to run. Whenthe fan is running it proves (switches) the airpressure switch. The air pressure switch deliverscurrent to the PCB and enables an ignition se-quence to begin. The ignition sequence beginswith the energising of the gas valve and a simul-taneous sparking at the spark/sense electrode.This will continue for aproximately 10 seconds oruntil successful ignition has been established. (Ifno ignition has been established within the tenseconds, the ignition attempt will be terminatedand the appliance will go to lockout). When ignitionhas been established, the appliance will quicklyachieve and maintain the desired hot water tem-perature (see 5.13). The appliance monitors thesetting of the hot water potentiometer against thetemperature of the secondary thermistor, andincreases or decreases current to the modulatingcoil, this in turn adjusts the burner pressure, thusenabling the temperature to be maintained towithin a few degrees. When the temperature ofthe secondary thermistor exceeds the setting ofthe hot water potentiometer, ignition will be termi-nated until the temperature drops.NOTEThe primary thermistor will overide the secondarythermistor if the temperature of the primarythermistor exceeds 80 ºC.When the mode selector switch is set to heatingand hot water, the pump will over-run for 30seconds after any demand for heating or waterhas been satisfied.When the mode selector switch is set to hot wateronly, the fan will over-run for one minute if thetemperature of the primary thermistor exceeds55 ºC.

7.4 HEATING MODEWith all controls calling for heat, the pump and fanwill run. When the fan runs it proves the air

SECTION 7 CHECKS, ADJUSTMENTS AND FAULT FINDING

pressure switch. The air pressure switch deliverscurrent to the PCB and enables an ignitionsequence to begin. The ignition sequence beginswith the energising of the gas valve and asimultaneous sparking at the spark/senseelectrode. This will continue for approximately 10seconds or until successful ignition has beenestablished. (If no ignition has been establishedwithin the ten seconds, the ignition attempt will beterminated and the appliance will go to lockout).The appliance monitors the setting of the heatingpotentiometer against the temperature of theprimary thermistor, and increases or decreasescurrent to the modulating coil, this in turn adjuststhe burner pressure, thus enabling thetemperature to be maintained to within a fewdegrees (see section 5.10). When the temperatureof the primary thermistor exceeds the setting ofthe heating potentiometer, ignition will beterminated and the appliance will anti-cycle forthree minutes (timer delay). When a new ignitionsequence begins the output of the appliance isset at minimum for two minutes.NOTEAny demand for hot water has the priority.If there is a demand for hot water whilst theappliance is anti-cycling, the timing will be can-celled once the demand for hot water has beensatisfied.

7.5 FROST PROTECTION MODEThe built-in frost protection system will operatethe appliance in the OFF, HOT WATER ONLYMODE, AND HEATING AND HOT WATERMODE. Should the temperature of the appliancefall to 7 ºC. the pump will run for fifteen minutes, thiswill be repeated every two hours. Should thetemperature rise above 10 ºC. the fifteen minuteswill be cancelled. Should the temperature fall below5 ºC. the boiler will fire at minimum output until thetemperature of the appliance exceeds 30 ºC.NOTEIf the appliance is at lockout the frost protectionmode is disabled.Although the frost protection mode is active evenwhen the appliance is switched off. The electricalsupply to the appliance must be maintained for itto function.Any demand for hot water or heating will resetany frost protection settings.

7.6 BURNER PRESSURE SETTINGSBurner pressure settings should be checked and/or adjusted whenever the appliance is beingserviced, commissioned, or the gas valve/controlPCB have been replaced.The procedure for setting or adjusting must becarried out in the following order:● set the maximum DHW gas pressure● set the minimum DHW gas pressure● set the maximum heating gas pressure● set the minimum heating gas pressure.

23Compact

7.6.1 SETTING THE MAXIMUM DHW GASPRESSURE (fig. 15 & 23)Isolate the appliance from the electrical supply,remove the appliance casing as described insection 4.7.1.● Attach a manometer to the outlet test point of

the gas valve.● Remove the protective cover from the gas

valve modulator, and disconnect thecompensation tube from the gas valve.

● Fully open a hot water outlet (preferably thebath tap).

● Rotate the DHW temperature selector tomaximum.

● Restore the electrical supply to the appliance.● The appliance will now light and after 7-10

seconds, the burner will be at full power.● Observe the manometer, the reading for

Compact 24 should be 10.1 mbar, for Compact28 the reading should be 10.2 mbar.

● If the reading is correct, proceed to section7.6.2

● If the reading is incorrect, turn the maximumadjustment screw (fig. 15) clockwise to increasethe pressure, or anti-clockwise to reduce thepressure.

● Proceed to section 7.6.2

7.6.2 SETTING THE MINIMUM DHW GASPRESSURE (fig. 15 & 23)● After carrying out section7.6.1, disconnect one of

the black wires attached to the modulator coil.● The burner will now operate at minimum power.● Observe the manometer, the reading for

Compact 24 should be 1.5 mbar, for Compact28 the reading should be 1.3 mbar.

● If the reading is correct, proceed to section 7.6.3.● If the reading is incorrect, turn the minimum

adjustment screw (fig. 15) clockwise to increasethe pressure, or anti-clockwise to reduce thepressure.

● Proceed to section 7.6.3

7.6.3 SETTING THE MAXIMUM AND THE MINIMUMCENTRAL HEATING BURNER PRESSURES● Isolate the appliance from the electrical supply.● Close the hot water outlet.● Re-attach the black wire to the modulator coil.● Remove the PCB cover and temporarily attach

a jumper tag to JP2.● Rotate the heating temperature selector to

maximum, and ensure all radiators are turnedon with any thermostatic radiator valves set tomaximum.

● Restore the electrical supply and ensure thereis a call for heat via the appliance time clockand/or room thermostat.

● The appliance should now be operating in theheating mode at maximum output.

● Observe the manometer, the – maximum –reading for Compact 24 should be 10.1 mbar,for Compact 28 the reading should be 10.2mbar

● Using a small screwdriver, gently rotate the P5potentiometer if adjustment is necessary.

● To check and/or adjust the minimum heatinggas pressure, slowly rotate the heatingtemperature selector until the burner pressuredrops to minimum (should be 1.9 mbar).

● Using a small screwdriver, gently rotate the P4potentiometer if adjustment is necessary.

● Isolate the appliance from the electrical supply,and remove the jumper tag from JP2.

● Remove the manometer from the gas valveand tighten the outlet test screw.

● Refit the PCB cover and appliance casing.

7.7 COMBUSTION ANALYSIS TESTThe appliance has a built-in facility which enablescombustion analysis checks to be carried out. Toactivate the combustion analysis mode, proceedas follows.Locate and remove combustion test point screw,(fig. 1) insert flue gas analyser probe into com-bustion test point, remove mode selector switchand rotate selector shaft clockwise until it can gono further, wait until the yellow LED begins toflash, turn the selector shaft back to the heatingposition. The appliance will now enter its com-bustion analysis mode whereby it will fire atmaximum output in the heating mode for fifteenminutes, without modulating until the maximumoperating temperature is realised. To gain accu-rate information, ensure the flue gas analyserhas been set properly, and that the analysis iscarried out when the appliance is on maximumoutput. Once the analysis has been completed,re-fit the mode selector switch, remove the fluegas analyser probe and replace the test pointscrew.

7.8 CHECKING THE EXPANSION VESSELCarry out procedure as described in section 6.5.Using a suitable pressure gauge, remove dustcap on expansion vessel and check the chargepressure. The charge pressure should be between0.7 – 0.8 bar. If the charge pressure is less, usea suitable pump to increase the charge. Pleasenote, you must ensure the safety valve is in theopen position whilst re-charging takes place.Replace dust cap and carry out the relevantcommissioning procedures as detailed in section6.21.

7.9 ELECTRO-MECHANICAL FAULTSBefore carrying out any fault finding or compo-nent replacement, ensure the fault is not attribut-able to any aspect of the installation, for example,external wiring fault, hot & cold services reversed,service valves closed, gas supply turned off, etc.

24 Compact

7.11 ELECTRICAL CHECKSAny electrical checks must be carried out by asuitably qualified person.

7.11.1 EARTH CONTINUITY TESTIsolate the appliance from the electrical supply,and using a suitable multi-meter carry out aresistance test. Connect test leads between anappliance earth point and the earth wire of theappliance supply cable. The resistance shouldbe less than 1 ohm. If the resistance is greaterthan 1 ohm check all earth wires and connectorsfor continuity and integrity.

7.11.2 SHORT CIRCUIT CHECKIsolate the appliance from the electrical supply,and using a suitable multi-meter, carry out a shortcircuit test between the Live & Neutral connec-tions at the appliance terminal strip (fig. 14).Repeat above test on the Live & Earth connec-tions at the appliance terminal strip (fig. 14).NOTEShould it be found that the fuse has failed but nofault is indicated, a detailed continuity check willbe required to trace the fault. A visual inspectionof components may also assist in locating thefault.

7.11.3 POLARITY CHECKWith the appliance connected to the electricalsupply and using a suitable multimeter, carry outthe following voltage tests. Connect test leadsbetween the Live & Neutral connections at theappliance terminal strip (fig.14); the meter shouldread aproximately 230V ac. If so proceed to nextstage. If not, see section 7.11.4.Connect test leads between the Neutral & Earthconnections at the appliance terminal strip (fig.14);the meter should read aproximately 0 – 15Vac. Ifso polarity is correct. If not, see section 7.11.4

7.11.4 REVERSED POLARITY OR SUPPLY FAULTRepeat the above tests at the appliance isolator,if testing reveals correct polarity and/or supply at

the isolator, re-check wiring and connectionsbetween the isolator and the appliance.If tests on the isolator also reveal reversed polarityor a supply fault, consult the local electricitysupplier for advice.

7.11.5 RESISTANCE TO EARTH CHECKIsolate the appliance from the electrical supply,and using a suitable multi-meter carry out aresistance test. Connect test leads between theLive & Earth connections at the appliance terminalstrip (fig.14). If the meter reads other than infinitythere is a fault which must be isolated, carry outa detailed continuity check to identify the locationof the fault.IMPORTANTThese series of checks must be carried outbefore attempting any fault finding procedures onthe appliance. On completion of any task whichrequired the disconnection and re-connection ofany electrical wiring or component, these checksmust be repeated.

7.11.6 FUSESThe appliance is equipped with spare fuses.These fuses are located on the cover of the mainPCB. If a fuse has blown it is usually indicative ofan external wiring fault or a faulty componentsuch as the pump, fan, valve actuator, etc. Underno circumstances should a blown fuse be replacedwith one of a higher rating.

7.12 FAULT FINDINGBEFORE ATTEMPTING ANY FAULTDIAGNOSIS OR REPAIR THE FOLLOWINGPROCEDURE SHOULD BE CARRIED OUT:● Carry out the relevant electrical checks as

detailed in section 7.11● Disconnect any external wiring from the room

thermostat connections of the applianceterminal strip and replace with a solid link wire.

● Ensure the appliance is protected – externally– by a 3 amp fuse.

FAULT POSSIBLE CAUSES REMEDY

APPLIANCE FIRES THEN LOCKOUTS INCORRECT GAS PRESSURE CHECK INCOMING PRESSURE

AND/OR BURNER PRESSURES

FLUE BLOCKED OR BROKEN CHECK FLUE ASSEMBLY

APPLIANCE WON’T FIRE FOR HOT WATER HOT & COLD PIPES REVERSED CHECK EXTERNAL PLUMBING

FLOW REGULATOR BLOCKED REMOVE AND CLEAN

INSUFFICIENT FLOW RATE INCREASE FLOW RATE

APPLIANCE WON’T FIRE FOR HEATING EXTERNAL CONTROL OR

WIRING FAULT CHECK EXTERNAL CONTROLS

OR WIRING

APPLIANCE FIRES FOR HEATING FLOW & RETURN SERVICE

BUT NO CIRCULATION AROUND SYSTEM VALVES CLOSED OPEN SERVICE VALVES

AIR IN APPLIANCE OPEN DUSTCAP ON ‘AAV’

PUMP STUCK OPEN VENT PLUG ON PUMP AND

ROTATE SHAFT

DEBRIS IN SYSTEM FLUSH SYSTEM

APPLIANCE INACTIVE NO ‘LED’s ELECTRICAL SUPPLY FAULT CHECK SUPPLY TO APPLIANCE

SHOWING FOR 240V BETWEEN ‘L’ & ‘N’

BLOWN FUSE CHECK AND REPLACE

7.10 POSSIBLE INSTALLATION FAULTS

25Compact

7.12.1 FAULT FINDING TEST ‘A’: CHECKING OPERATION OF ELECTRONIC CONTROL BOARD ATSTART UP

MAINS ON FAN

REPLACE FAN

YES

NO

YES

REPLACE WIRINGOR CONNECTIONS

MAINS ON PUMP

REPLACEPUMP

NO

YES

YES

YESNO

NO

A1

A

CHECK &/ORREPLACE WIRING

ANDCONNECTIONS

MAINS ON FAN

CONNECTOR CN4.1 & CN4.2

ON PCB

MAINS ON PUMP CONNECTOR

CN2.1 & CN2.2ON PCB FAN RUNNING

PUMP RUNNING

GREEN LEDBLINKS

START

NO

NO

YES

REPLACE WIRINGOR CONNECTIONS

AIR FLOW SWITCH

OFF?

REPLACE AIRFLOW SWITCH ORCHECK FLUE GAS

TUBE

YES

REPLACECONTROL BOARD

ISTHERE 0 VCC

BETWEEN TERMINALS CN8.3 & CN8.5

ON PCB

NO

NO

YES

MADE A LINK BETWEEN BLACK &BLACK WIRES AT BOILER

TERMINAL STRIP AND CLOSE THETIMER CONTACT

SWITCH ON BOILER ANDSELECT MODE TO

WINTER C/HTHERMOSTAT AT MAX.

YES

LOOSE THE PUMPACTING WITH A

SCREWDRIVER ONTHE IMPELLER

RESTART THETEST

NO

NO

NO

NO

IS ROOM THERMOSTATINPUT LINKED

MADE A LINKBETWEEN THE ROOMTHERMOSTAT INPUT

CHECK IDRAULICCIRCUIT

WATERPRESSURE SWITCH

IS OK

NO

ISTHERE 24dc

BETWEEN TERMINALS CN8.3 & CN8.5

ON PCB

REPLACECONTROL BOARD

YESIS

THERE 24dc BETWEEN TERMINALS

CN9.1 & CN9.2 ON PCB

CHECK WIRING ANDCONNECTIONS ORWATER PRESSURE

SWITCH

MAINSBETWEEN PIN CN1.4 & CN1.5

ON PCB

REPLACECONTROL BOARD

RESTART THETEST

CHECK WIRING ORCONNECTIONS

BETWEEN TERMINALSTRIP AND CONTROL

BOARD

YES

YES

YES

YES

NO

NO

PUMP RUNNING

YES

26 Compact

7.12.2 FAULT FINDING TEST ‘A’

YES

NO

NO MAINS ON E.V.G.

NO

YES

NO

NO

YES

YES

YES

NO

IS THERE 24 Vdc

BETWEEN TERMINALSCN8.4 & CN8.5

ON PCB

A

REPLACESENSING/SPARKELECTRODE AND

LEADREPLACE PCB

SENSINGSPARK ELECTRODE

AND LEAD OK

CHEKSENSING/SPARKELECTRODE AND

LEAD

END

LOCKOUT

IGNITION

REPLACE EVGCHECK GAS

EVG OK

IGNITION

SPARK ATELECTRODE

CHECK WIRING ANDCONNECTIONS OR

HIGH LIMIT THERMOSTAT

CHECKSENSING/SPARKELECTRODE AND

LEAD

ISTHERE 230 Vac

BETWEEN TERMINALSCN5.1 & CN5.2

ON PCB

ISTHERE 0 Vdc

BETWEEN TERMINALS CN8.7 & CN8.8

ON PCB

NO

YES

NO

CHECK WIRINGAND

CONNECTIONS

NO

DO THEAIR FLOW SWTCH

TURN ON

CHECK WIRING ANDCONNECTIONS, AIR FLOW

SWITCH AND CONTROLBOARD

YES

NO

ARE THEVENTURI TUBE

AND THE SILICONE AIR TUBES

CLEANCHECK/CLEAN THEVENTURI TUBE AND

SILICONE AIRTUBES

ISTHE AIR DP >11 mmCH2O

CHECK THE FANAND/OR FLUE GAS

TUBE

CHECK REPLACEAIR FLOW SWITCH

NO

YES

YES

REPLACE THECONTROL BOARD

YES

NO

NO

IS THERE 230 Vac

BETWEEN TERMINALSCN6.1 & CN6.2

ON PCB

CHECK AND/ORREPLACE PCB

IS THERE 24 Vdc

BETWEEN TERMINALSCN8.4 & CN8.8

ON PCB

CHECK AND/ORREPLACE PCB

IS THERE 24 Vdc

BETWEEN TERMINALSCN8.4 & CN8.7

ON PCB

NO

CHECK WIRING ANDCONNECTIONS OR

HIGH LIMITTHERMOSTAT

NO

YES

YES

YES

AFTER

27Compact

7.12.3 FAULT FINDING TEST ‘A1’

NO

YES

A1

REPLACECONTROL BOARD

FUSE OK

CHECK FUSE F1ON CONTROL

BOARD

RED LEDBLINKS

MAINS PRESENT BETWEEN

TERMINALS CN1.2&CN1.3 M2.2 ON

CONTROL

YES

NO

RESTART THETEST

REPLACE FUSE

NO

NO

REPLACE CONTROLBOARD

RED LEDLIGHT

YES

YES

SWITCH ON/OFFSELECTOR ON OFF

POSITION

SWITCH ON/OFFSELECTOR TO

WINTER POSITION

GREEN LEDBLINKS

RESTART THETEST

YES

YES

NO

CHECK CH NTCSENSOR OR WIRINGAND CONNECTIONS

YELLOW LEDLIGHT

NO

CHECK WIRING ANDCONNECTIONS, WATERPRESSURE SWITCH AND

HYDRAULIC CIRCUIT

NO

RECHECK SUPPLYFUSE &

CONNECTORS TOBOILER

TERMINALS

MAINS PRESENT BETWEEN

BLUE & BROWN WIRES ATBOILER TERMINAL

STRIP

NO

REPLACE WIRING ORCONNECTIONS

TERMINAL STRIP ANDCONTROL BOARD

YES

YELLOW LEDBLINKS

CHIMNEYSWEEPER CYCLE.

RESET ANDRESTART TEST

NO

ISTHERE 0 VCC

BETWEEN TERMINALS CN9.1 & CN9.2

ON PCB

ISTHERE 24 Vdc

BETWEEN TERMINALS CN8.4 & CN8.7

ON PCBIS

THERE 24 Vdc BETWEEN TERMINALS

CN8.4 & CN8.8 ON PCB

REPLACECONTROL BOARD

CHECK WIRING ANDCONNECTIONS OR

HIGH LIMIT THERMOSTAT

ISTHERE 24 Vdc

BETWEEN TERMINALS CN8.4 & CN8.6

ON PCB

REPLACECONTROL BOARD

ISTHERE 24 Vdc

BETWEEN TERMINALS CN8.4 & CN8.5

ON PCB

CHECK WIRING ANDCONNECTIONS OR

AIR PRESSURE SWITCHREPLACE

CONTROL BOARD

YES

YES

YES

YES

YES

NO

NO

NO

NO

YES

BOARD

28 Compact

7.12.4 FAULT FINDING TEST ‘B’: CHECK CONTROL IN DHW MODE

NO

NO

NO

NO

NO

YES

YES

YES

ISVOLTAGE

ACROSS TERMINALSOF MODULATOR

COIL >10 VDC

REPLACE WIREAND

CONNECTIONS

REPLACECONTROL BOARD

REPLACEMODULATOR COIL

IS THE RESISTENCE OF

MODULATOR COIL ABOUT 70/80

OHM

ISTHERE A

VOLTAGE >10 VDCBETWEEN TERMINALS

CN9.7 & CN9.8 ON PCB

DOES BURNER LIGHT

CHECK BOILERSTARTUP: TEST A

TURN ON TAP

SWITCH ON BOILER ANDSELECT MODE TO

SUMMER. DHWTHERMOSTAT AT MAX.

START

YES

SWITCH DHWTHERMOSTAT AT MIN.

DO BURNER AND FAN

SWITCH OFF

IS

TEMPERATURE >40 ˚C

WAIT D.H.W.TEMPERATURE

>40 ˚C

REPLACECONTROL BOARD

YES

NO

YES

NO

ISTHERE 24 Vdc

BETWEEN TERMINALS CN9.7 & CN9.8

ON PCB

REPLACECONTROL

BOARD

YES

CHECK WIRING ANDCONNECTIONS OR

DHW SWITCH

YES

NO

ISTHERE 0 Vdc

BETWEEN TERMINALS CN9.7 & CN9.8

ON PCB

NO

WAIT TILL THEVOLTAGE BETWEEN

TERMINAL CN9.3 & CN9.4 ON PCB IS < 1.2 Vdc

IS THEVOLTAGE BETWEENTERMINAL CN9.3 &CN9.4 ON PCB IS

< 1.2 VdcIS

TEMPERATURE >60 ˚C

WAIT D.H.W.TEMPERATURE

>60 ˚C

YES

YES

NO

ISD.H.W. NTC

OK

REPLACE D.H.W. NTC

REPLACECONTROL BOARD

YES

B

NO

D.H.W.

D.H.W.

29Compact

7.12.5 TEST ‘B’ CONT’D

NO

END

DO BURNER, FAN AND

PUMP SWITCH OFF

TURN OFF TAP

SWITCH DHWTHERMOSTAT AT MAX.

DO BURNER AND FAN

SWITCH ON

IS

TEMPERATURE >60 ˚C

WAIT D.H.W.TEMPERATURE

< 60 ˚C

REPLACECONTROL BOARD

YES

CHECK WIRING ANDCONNECTION ORCONTROL BOARD

REPLACE DHWFLOW SWITCH

IS DHW FLOW

SWITCH OK

YES

YES

NO

NO

YES

NO

B

D.H.W.

30 Compact

7.12.6 FAULT FINDING TEST ‘C’: CHECK CONTROL IN C/H MODE

NO

YES

NO

YES YES

NO

YES NO

REPLACECONTROL BOARD

REPLACECONTROL BOARD

REMOVE JUMPER

IS TIMER JUMPER

ON

ISVOLTAGE

ACROSS TERMINALS OFMODULATOR COIL

>10 VDC

ISVOLTAGE

ACROSS TERMINALS OFMODULATOR COIL

< 8 VDC

CHECK BOILERSTARTUP TEST A

SET TIMERJUMPER ON

DOES BURNER

LIGHT

MADE A LINK BETWEENBLACK & BLACK WIRES AT

BOILER TERMINALSTRIP AND CLOSE THE

TIMER CONTACT

SWITCH ON BOILERAND SELECT MODE

TO WINTER C/HTHERMOSTAT AT

MAX.

START

RESTART THETEST

NO

NO

YES

REPLACE WIREAND

CONNECTIONS

REPLACECONTROL BOARD

REPLACEMODULATOR COIL

IS THE RESISTENCE OF

MODULATOR COILABOUT 70/80

OHM

ISTHERE A

VOLTAGE <8 VDCBETWEEN TERMINALS

CN9.3 & CN9.4 ON PCB

YESC

ISVOLTAGE

ACROSS TERMINALS OFMODULATOR COIL

>10 VDC

SWITCH CHTHERMOSTAT AT MIN.

NO

YES

NO

WAIT TILL THEVOLTAGE BETWEEN

TERMINAL CN9.3 & CN9.4 ON PCB IS < 1.2 Vdc

IS THEVOLTAGE BETWEENTERMINAL CN9.3 &CN9.4 ON PCB IS

< 1.2 Vdc

IS

TEMPERATURE >80 ˚C

WAIT D.H.W.TEMPERATURE

>80 ˚C

YES

NO

YES

NO ISC.H. NTC

OK

REPLACE C.H. NTC

REPLACECONTROL BOARD

YES

D.H.W.

31Compact

7.12.7 TEST ‘C’ CONT’D

YES

WAIT 3 MIN.

C

NO

DO BURNER AND FAN

SWITCH OFF

ISWATER FLOWTEMPERATURE

>40 ˚C

WAIT WATER FLOWTEMPERATURE

>40 ˚C

REPLACECONTROL BOARD

SWITCH CHTHERMOSTAT AT MAX.

DO BURNER AND FAN

SWITCH ON

ISWATER FLOWTEMPERATURE

>80 ˚C

WAIT WATER FLOWTEMPERATURE

< 80 ˚C

NO YES

REPLACECONTROL BOARD

REMOVE JUMPER

IS TIMER JUMPER

ON

RESTART THETEST

DO BURNER AND FAN

SWITCH ON

OPEN THE TIMERCONTACT

REPLACECONTROL BOARD

DO BURNER

AND FAN SWITCH

OFF

DOPUMP SWITCH

OFF

END

REPLACECONTROL BOARD

YES

YES

YES

NO

NO

NO

NO

NO

NO

YES

YES

YES

WAIT30 SECS.

NO

ISC.H. NTC

OK

REPLACE C.H. NTC

REPLACECONTROL BOARD

YES

32 Compact

SECTION 8 WIRING DIAGRAMS

Fig. 29

Fig. 29A

8.1 CONNECTION OF A ROOM THERMOSTAT(fig. 29 & 29A)Isolate the appliance from the electrical supply.Remove the appliance casing and PCB cover.Connect the room thermostat as shown in diagramfig. 29. A neutral supply can be taken from theappliance terminal strip if required. Carry out theelectrical checks as described in section 7.11prior to refitting the PCB cover and appliancecasing.

8.2 CONNECTION OF AN EXTERNAL TIMECLOCKShould the integral time clock be unsuitable,additional or alternative controls must beconnected to the appliance terminal strip as shownin fig. 29 & 29A.

NOTEGuidance on the recommended practice for theinstallation of external controls, can be found inCHeSS – HC1/HC2 (www.energy-efficiency.gov.uk).

33Compact

FUNCTIONAL DIAGRAM

NOTE: L-N-E CONNECTION IS ADVISABLE

Key

R.T. Room thermostatS.F.S. Domestic hot water flow switchP.S. Pressure switchP.D.S. Differential pressure switchH.L. High limit thermostatS.R. Heat thermistorS.S. Domestic hot water thermistorMOD ModulatorF FanP PumpSP/SE E. Spark\Sense electrodeOPE Gas valve solenoidsB.C.B. Burner control boardCP08X Boiler control boardJP2 Setting timerJP3 Natural gas or L.P.G. selector

JP4 Jumper disable/enable DHW absolut thermostatP1 Domestic hot water temperature controlP2 Central heating temperature controlP3 Off/summer/winter selectorP4-P5 Setting trimmerF External fuse 2 A F (on 230 V circuit)F2 (CP08X) Fuse 2 A F (on 230 V circuit)RL1 Ignition relayRL2 Fun relayRL4 Pump relayTRF1 TrasformerTRX Ignition trasformerACF01X Ignition control boardLED Led OK (green)

Led alarm (red)Combustion test (blink orange)

Fig. 30

34 Compact

NOTE: L-N-E CONNECTION IS ADVISABLE

FUNCTIONAL DIAGRAM

Fig. 31

35Compact

SECTION 9 EXPLODED DIAGRAMS

270

13

26

20

12

21

27

2827

226

18

19

76

49

3331

226

90

1

300

301

302

POS. DESCRIPTION 24 28

1 Frame assembly 01005259 0100526012 Quick primer pressure gauge 10024019 1002401913 Pin 10023044 1002304418 Cover 10023812 1002381219 Ignition module 10022174 1002217420 Printed Circuit Board 10023537 1002353721 Led Light Guide 10023816 1002381626 Instrumental panel 10023933 1002393327 Knob 10023937 1002393728 Knob 10023936 1002393631 Case 10023822 1002388333 Plastic Trade Mark Label 1979 197949 Converter 10023935 1002393576 Timer 10023938 1002393890 3 A fuse 3478 3478

226 Edge clip 5128 5128270 Transformer 10021272 10021272300 Wiring harnes 10023939 10023939301 Wiring harnes 10024067 10024067302 Wiring harnes 10023840 10023840

36 Compact

2728

35130

27

353

26

3 2

7

288

288

288

300303

289

28922

289

303

289

31289

290

23

201

299

285

36

25

201

353

63

24

POS. DESCRIPTION 24 28

2 Connection 10022658 100226583 Pressure switch 2044 20447 By-pass valve 2047 2047

22 Safety valve 1806 180623 Connection 10022499 1002249924 Flow governor 8009 800925 Pipe 10020714 1002395026 DHW actuator 10022349 1002234927 Heating cock 1789 178928 Connection 1790 179030 Water supplu stop cock 7099 709931 Venting plugs kit 01005137 0100513736 Pipe 10020612 1002394963 Pipe 10020898 10020898

201 Washer 5026 5026285 NTC sensor 8484 8484288 O ring 6898 6898289 Clip 2223 2223290 Clip 2165 2165299 Washer 10022726 10022726300 Clip 2222 2222303 Connection 2217 2217351 Brass nut 1823 1823353 Ogive 1824 1824

37Compact

1

2

201

7

9

3

289

12

8

289

290

289

290

285202

287

10

12

POS. DESCRIPTION 24 28

1 Expansion vessel 2204 22042 Flexible pipe 2164 21643 Pump 2225 22257 Pipe 10022000 100239478 Heat exchanger 10021419 100236619 Pipe 10022002 10023948

10 Automatic air vent bottle 0439 043912 Washer 2226 2226

201 Washer 5026 5026202 Washer 5041 5041285 NTC senspr 8484 8484287 High limit thermostat 2258 2258289 Clip 2223 2223290 Clip 2165 2165

38 Compact

18

16

5

4

3

200

15

200

13

295

12

200 1

52

27

53

200

2

14

53

27

1

2

18

16

24 CSI

POS. DESCRIPTION 24 28

1 Roomsealed chamber 10023931 100239452 Clip 0442 04423 Main burner injector manifold 10023799 100239023 Main burner injector manifold 10023800 100239034 Burner 10023798 100239015 Spark electrode 10021398 10021398

12 Pipe 10023996 1002399613 Gas valve 10021021 1002102115 Gas cock 10020897 1002089716 Cover assembly 10021570 1002392818 Glass 10021558 1002155827 Air box hole cap 8084 1002380552 Burner flange - 1002399753 Nut 2233 2233

200 Washer 5023 5023295 Silicone tube 1457 1457

- LPG conversion kit - 01005262

39Compact

4

25

212

2

3

1228

20 295

10

300

3

POS. DESCRIPTION 24 28

2 Back insulating panel 2230 100239093 Lateral insulating panel 2231 22314 Front insulating panel 2232 10023910

10 Fan 10020793 1002390712 Connection 2237 223720 Fumes testing connection pipe 10020627 1002062725 Pressure diff. switch 8195 1002390828 Stop clip 10020626 10020626

212 Screw 5080 5080295 Silicone tube 1457 1457300 Wiring harnes 10024067 10024067

40 Compact

10.1 TECHNICAL DATA

SECTION 10 L.P.G. INSTRUCTIONS

10.3 GAS SUPPLYThe gas supply must be connected to the applianceby a competent L.P.G. installer and must be ofsufficient size to supply the appliance at its maxi-mum output. An existing supply must be checked toensure that it is of adequate size to deal with themaximum rated input of this and any other appliancesthat it serves.

10.4 GAS SUPPLY INSTALLATIONThe entire installation including the meter, must bepurged and checked for gas soundness.

10.5 BURNER PRESSURESBurner pressure settings should be checked and/oradjusted whenever the appliance is being serviced,commissioned, or the appliance gas type haschanged.NOTEEnsure the jumper tag has been fitted to the controlPCB (JP3).The procedure for setting or adjusting must becarried out in the following order:● set the maximum DHW gas pressure.● set the minimum DHW gas pressure.● set the maximum heating gas pressure.● set the minimum heating gas pressure.

10.5.1 SETTING THE MAXIMUM DHW GAS PRESSURE(fig. 15 & 23)Isolate the appliance from the electrical supply,remove the appliance casing as described in 4.7.1.● Attach a manometer to the outlet test point of the

gas valve.● Remove the protective cover from the gas valve

modulator, and disconnect the compensation tubefrom the gas valve.

● Fully open a hot water outlet (preferably the bath tap).● Rotate the DHW temperature selector to

maximum.● Restore the electrical supply to the appliance.● The appliance will now light and after 7-10 seconds,

the burner will be at full power.● Observe the manometer, the reading should be

36.0 mbar.● If the reading is correct, proceed to section 10.5.2● If the reading is incorrect, turn the maximum

adjustment screw (fig. 15) clockwise to increasethe pressure, or anti-clockwise to reduce thepressure.

● Proceed to section 10.5.2.

BURNER PRESSURES COMPACT 24 COMPACT 28Inlet pressure 37 mbar 37 mbar

Gas rate 2,04 Kg/h 2,41 Kg/h

Injectot size 12 x 0.77 14 x 0.77

Maximum burner pressure DHW & Heating 36 mbar 36 mbar

Minimum burner pressure DHW 5.1 mbar 4.8 mbar

Minimum burner pressure Heating 6.5 mbar 6.5 mbar

Jumper tag for LPG Inserted across JP3 Inserted across JP3

10.5.2 SETTING THE MINIMUM DHW GAS PRESSURE(fig. 15 & 23)● After carrying out section 10.5.1, disconnect one

of the black wires attached to the modulator coil.● The burner will now operate at minimum power.● Observe the manometer, the reading for Compact

24 should be 5.1 mbar, for Compact 28 thereading should be 4.8 mbar.

● If the reading is correct, proceed to section 10.5.3.● If the reading is incorrect, turn the minimum

adjustment screw (fig. 15) clockwise to increasethe pressure, or anti-clockwise to reduce thepressure.

● Proceed to section 10.5.3.

10.5.3 SETTING THE MAXIMUM AND MINIMUMCENTRAL HEATING BURNER PRESSURES● Isolate the appliance from the electrical supply.● Close the hot water outlet.● Re-attach the black wire to the modulator coil.● Remove the PCB cover and temporarily attach a

jumper tag to JP2.● Rotate the heating temperature selector to

maximum, and ensure all radiators are turned onwith any thermostatic radiator valves set tomaximum.

● Restore the electrical supply and ensure there isa call for heat via the appliance time clock and/orroom thermostat.

● The appliance should now be operating in theheating mode at maximum output.

● Observe the manometer, the – maximum – readingshould be 36.0 mbar.

● Using a small screwdriver, gently rotate the P5potentiometer if adjustment is necessary.

● To check and/or adjust the minimum heating gaspressure, slowly rotate the heating temperatureselector until the burner pressure drops to minimum(should be 6.5 mbar).

● Using a small screwdriver, gently rotate the P4potentiometer if adjustment is necessary.

● Isolate the appliance from the electrical supply,and remove the jumper tag from JP2.

● Remove the manometer from the gas valve andtighten the outlet test screw.

Refit the PCB cover and appliance casing.

For details of converting appliances to LPG please refer to the instructions supplied with the relevant conversation kit.

BS 6798 INSTALLATION OF BOILERS OF RATED INPUT NOT EXCEEDING 60 Kw

BS 5449 PART 1 FORCED CIRCULATION HOT WATER SYSTEMS

BS 5546 INSTALLATION OF GAS HOT WATER SUPPLIES FOR DOMESTIC PURPOSES

BS 5440 PART 1 FLUES

BS 5482 PART 1 DOMESTIC BUTANE & PROPANE GAS BURNERS IN PERMAMENT DWELLINGS

10.2 RELATED DOCUMENTS

41Compact

SECTION 11 REAR FLUE

Fig. 33 Fig. 34

M a x

Min 200

D A C B

Fig. 32

11.1 FITTING THE FLUE (see fig. 33)There are two telescopic flue kits for use with theOption boiler. The standard telescopic flue issuitable for a wall thickness of 200 mm – 425mm. The extended telescopic flue is suitable fora wall thickness of 425 mm – 760 mm. Pleaseensure the flue kit you have is suitable.Carefully open the flue pack. Contained withinthe pack are:● The outer concentric flue pipe with terminal● The inner concentric flue pipe● Exterior trim● Large rubber gasket● Locking collar● Securing screwCarefully measure the thickness of the wall (di-mension x - fig. 33). Take the outer concentricflue pipe (A) and – using a twisting action – easeit over the inner concentric flue pipe (B) (fig. 34).Add 210 mm to ‘x’ to give you dimension ‘y’. Pushboth the inner and outer concentric flue pipestogether until the total length of the flue assem-bly is equal to dimension ‘y’. Secure the flueassembly in place by using the screw provided(C).Take the large rubber gasket and secure it firmlyover the appliance flue spigot (D). Pass the as-sembly through the wall mounting bracket andwall leaving 25 mm proud of the wall-mountingbracket. Insert the flue restrictor ring into theappliance flue outlet.The appliance can now be mounted to the wallbracket.

Pull the flue assembly firmly towards and overthe appliance flue spigot (fig. 34A) and – using atwisting action – ensure the correct seal is made.Insert the locking collar (E) into the groove onthe flue assembly as shown in fig. 34 a and ro-tate to conceal.Seal the flue assembly to the inside wall usingcement or a suitable alternative that will providesatisfactory weatherproofing. The exterior trimcan now be fitted.

Fig. 34A

EE

3 .dE - 30/94 - 24932001 .doC

Registered address:Vokèra Ltd

Borderlake HouseUnit 7 Riverside Industrial Estate

London ColneyHerts AL2 1HG

enquiries@vokera.co.uk

www.vokera.co.ukwww.vokera.ie

Sales, General EnquiresT 0844 391 099

F 0844 391 0998

Vokèra IrelandWest Court, Callan

Co KilkennyT 056 7755057F 056 7755060

Vokèra Limited reserve the right to changespecification without prior notice

Consumers statutory rights are not affected.

A Riello Group Company.Company Reg No: 1047779