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Service ProceduresChapter 15

Chapter 15—Service Procedures 15-3

IntroductionThe most interesting and challenging

part of an Oilheat Service Technician’s jobis troubleshooting. Think of all the partsthat must work together for a system tofunction properly; if any one of thembecomes defective, the system will mal-function. Your job is like a detective’s—you mustfigure outwhat hap-pened, why ithappened, howto fix it andhow to keep itfrom happen-ing again.

The previ-ous chaptershave providedyou with anunderstandingof the opera-tion of the various components of Oilheatsystems. This chapter explains how to usethat knowledge to repair systems withoutwasting time or replacing parts that areworking properly.

Before you get involved with in-depthtroubleshooting, remember to check thebasics:

• Are all the switches on?

• Is the fuse blown or circuit breakertripped?

• Is the thermostat set above the roomtemperature?

• Is there oil in the tank?

• Is the blower door closed? (There isa switch on many blower doors thatprevents the system from operating ifit’s not properly closed.)

• Is there enough water in the steam orhot water system?

• Are the air filters clean?

There are many reasons for a customerto require your expertise, among themost common are:

• No heat

• Insufficient heat

• Too much heat

• No hot water

• Water leak

• Oil leak

• Odors, smoke or soot

• Oil tank and/or piping

• Thermostats, controls or electricsupply

• Heat distribution system

• Oilburner components

Using an electrical meter

Chapter 15Service Procedures

15-4 Service Procedures

You need to approach each problemcarefully and systematically.

Carefully—never do anything that canput you, other people, or property indanger.

Wear appropriate Personal ProtectiveEquipment and protect your work area with

drop cloths, newspaper or builder’spaper. Use insulated screwdrivers andavoid working on live electricalcircuits. Do not press reset buttonswithout first making sure that there isnot a fire or an oil buildup in thecombustion chamber.

Systematically—the best ServiceTechnicians develop standard trouble-shooting routines. They go from stepto step until they find and correct thecause of the problem.

A systematic approach starts withlogic—looking for the obvious solutionand then trying to narrow down the prob-lem. Start with the easy—if the heatingsystem is not working, check that allelectrical switches are turned on and thatthere is enough oil in the tank before youstart disassembling the oilburner.

Most importantly, NEVER assumeanything. Don’t assume that thereset was only pressed once;don’t assume that the lastservice technician installed thecorrect nozzle; don’t assumethat your dispatcher told youthe correct reason for the calland don’t assume that becausea customer says they haveplenty of oil that their tankisn’t empty.

An example of a systematictroubleshooting routine:

Step 1. Information gather-

ing: Effective troubleshooting starts beforeyou arrive at the customer’s home. Whenyour dispatcher gives you the call, try toget important data such as:

• What problem did the customerreport?

• When was the last oil delivery?

• When was the last tune-up?

• When was the last service call, andwhat was done?

When you arrive at the customer’shome, listen to what the customer says andask questions to clarify the situation.Depending on the type of trouble, you maywant to ask if any work has been donerecently that might have caused the situa-tion, such as other tradesmen working onthe electric or plumbing, or if a chimneysweep has just been performed.

Ask if they have pressed the resetbutton, how many times and what hap-pened after it was pressed.

Once you think you understand exactlywhat the problem is, proceed to theappliance area and on your way, check theelectrical switch and oil tank gauge. When

Wear protectiveequipment

Check service card



you get to the burner, read the service cardon the unit to see what work previoustechnicians have performed.

Step 2. The investigation: At this point,you know what the problem is (no heat)and what work has been recently per-formed. Now is time to narrow down yourinvestigation.

Assume that you find the primarycontrol is off on safety. You know that in anoilheat system, electricity flows from thecircuit breaker to a switch to the limitcontrols to the primary control to theburner components. Since the control is offon safety, you can eliminate everythingfrom the primary control back—the limitcontrols, switches or circuit breaker cannothave caused the problem.

You have determined that the problem isprobably the fuel supply, the primarycontrol or a burner problem. There couldalso be a low voltage situation. Use yourelectrical meter to check. If the voltage iscorrect, move on to the next step.

Step 3. Determine the problem: Next,protect the work area and remove thethermostat wires from the T-T terminals ofthe primary control (to prevent damage tothe thermostat). Install a jumper betweenthe terminals to simulate the thermostatcalling for heat throughout the rest of theservice call.

Open the observation door to check for aflame or excess oil in the chamber, if thereis no flame or oil, leave the door open toallow any excess pressure to escape in theevent of a delayed ignition when the burnerstarts.

Press the reset button and observe whathappens:

• If the burner ignites and runs properly

You can protectthe work area with

newspaper, builder’spaper or drop cloths.

Be careful whenusing drop clothsbecause they can

absorb oil andcause you to

bring a mess andodors to your

next call.

but shuts off on safety, youshould visually check thecad-cell eye and leads; andcheck the retention head forcarbon build up. If the eyeand/or retention head is dirty,clean them and continuetroubleshooting to determinewhy they’re dirty.

• If the eye and head areclean, disconnect the cad cellleads from the control, start theburner and install a 1,000-ohmresistor across the F-F terminalsto simulate a fire and connectyour ohmmeter to thedisconnected leads to checkthe resistance through the cad cell. If theresistance is high, the cell is either defec-tive or is not sighting the fire correctly. Ifthe resistance is below 1,500 ohms checkthe leads again, either they’re crimped orthe control is defective.

• If the burner starts but does not ignite,you know the problem is related to the

Ohmmeter connected to leads



combustion process. It could be an ignitionproblem, an oil problem or excess air.

• If nothing happens, the control mightbe sensing flame. The cad cell leads mightbe crimped together or the F-F terminalsmight be shorted.

• If the burner hums but does not start,the burner motor might be defective or thepump might be “bound” causing the motorto shut off on overload.

Step 4. The 5 Whys: ProfessionalService Technicians look beyond thesymptoms to find the cause of the problem.For example, if you press the reset buttonand the burner starts, you have not fixedanything. You have to find out why thecontrol went off on safety and take correc-tive action to keep it from happening again.

When you find the cause of a problem,ask yourself “why did this happen?”Continue to ask yourself the same questionand eventually you will get to the realcause of the problem. For example,suppose a customer has no heat. During

your systematic troubleshooting routine,you may find the following:

Sometimes you will find the answerwith less than five “whys”; sometimes itmight take more than five. The key is tokeep asking until you are satisfied that youknow the reason for the problem and thecorrective action to take.

Step 5. The “Hows”: Once you knowthe “whys” you need to correct the immedi-ate problem and keep it from happeningagain. “How” do you do that? In thesituation we just reviewed in the “5 Whys”the following steps are required:

1. Replace the vent pipe

2. Remove the water from the tank

3. Clean the oil lines

4. Replace the fuel unit

5. Replace the nozzle

6. Replace the oil filter

7. Reset the primary control (andburner motor if applicable)

8. Fire the unit

9. Adjust the burner and perform anefficiency test

In some situations, you might not havethe time, equipment or experience neces-sary to perform all of the “Hows”. In thatcase, you should troubleshoot the situationto the best of your ability and contact yoursupervisor for instructions on how toproceed.

Step 6—Paperwork and exit. Once youhave completed the “Hows,” clean up yourwork area, remove all debris to a receptaclein your service vehicle and clean yourhands.

Complete your company’s paperworkand fill in the service card at the unit. Take



a last look around to make sure that thearea is clean, that you have taken all yourtools, removed all jumpers and returned allcontrols and thermostats to their propersettings.

Give the customer the appropriate copyof the invoice, explain what you did and theefficiency test results and answer anyquestions they have. Thank them for theirbusiness and return to your vehicle to moveon to your next call.

Helpful hint: try to avoid unpluggingany electrical appliances when performingservice. If you must unplug anything, askthe customer for permission first and leaveyour truck keys tied to the cord to ensureyou will plug it back in before you leave.

Troubleshootingsuggestions

The following is intended to help youtroubleshoot typical problems that you arelikely to encounter. It is not a list of allpossible situations or each and every stepyou should take to troubleshoot problems.

#1 No heat—the unit is cold and theburner is not operating.

If the primary control has no power:

1. Check the limit controls. If the limitcontrol has power coming through it thereis a problem with the wiring between thelimit and the primary control. NOTE: Makesure you have checked all of the limitcontrols; for example—on a system withboth a high limit aquastat and a low watercut-off, you must make sure that both areallowing electricity to pass through to theprimary control.

2. If the limit control has no powercoming to it, check the switch. If there is nopower to the switch, check the circuitbreaker or fuse.

3. If you reset the circuit breaker andthe unit runs, do not leave right away

because something caused the breaker totrip. Use an ammeter to determine if any ofthe system components are malfunctioning.

If the primary control has the correctinput voltage, but no power is going to theburner motor, igniter or oil valve:

1. Check to be sure that there is not afire in the chamber. (Cad cell primaries willnot energize if a fire is sensed.)

2. Make sure that the thermostat is setwell above room temperature and the heatanticipator is set to the current draw of thecontrol circuit.

3. If the burner still does not start,disconnect the thermostat wires from the T-T terminals of the primary control andinstall a jumper.

If the burner starts, there is a problemwith the thermostat or its wiring.

4. If the burner still does not start,disconnect the cad cell leads from the F-Fterminals.

• If the burner starts, there is a problemwith the cad cell or its leads.

• If the burner does not start, check tobe sure that there is not a piece of wire orsomething else shorting out the F-Fterminals.

• If there is nothing shorting out the F-F terminals, the control is probablymalfunctioning. Use your ohmmeter toperform the test mentioned earlier.

If the primary control is passing thecorrect voltage through to the burnercomponents but:

A. Motor runs but no flame

1. Disconnect the nozzle line and checkthe oil flow. If water is found in the oil,drain it from the tank.

2. If the flow is good and water free,check the nozzle and ignition system (seenext section B, on following page.)



D. Burner fires but shuts off on safety

1. If a stack relay is installed:

• Check the helix, clean and/or reposi-tion as necessary.

• Check that there is sufficienttemperature in the flue.

2. If a cad cell control is installed:

• Check the cell, clean and re-positionas necessary.

• Check the air tube and end cone,clean/replace as necessary.

3. Check for water or air in the nozzle line:

• If water is found, drain it from thetank and lines

3. If there is no flow, check the oilsolenoid valve and bleed the pump.

4. If the pump cannot be primed, makesure all valves are open and check for oil(Stick the tank, the gauge may be wrong).

5. If there is sufficient oil, check the oilfilter and perform a vacuum test (seeChapter 4), the oil line or tank vent may beclogged.

6. If the vacuum is high, clean the oilline with a push-pull pump.

7. If the vacuum is low, check thecoupling.

8. If the coupling is good, check thepump strainer.

9. If everything checks OK, perform acomplete pump test (see Chapter 4.)

B. Motor runs with oil flowbut no ignition

1. Check the electrodes/porcelains/ignition cables for defects.

2. Check the electrode setting and nozzleposition.

3. Check the transformer connections.

4. Verify that correct primary voltage issupplied to ignition transformer/igniter.

C. Motor runs with oil pressure andignition but no flame

1. Check the nozzle and replaceif plugged.

2. Check the oil pressure, set to manu-facturer specs.

3. Check the air settings—adjust asnecessary (too much air can “blow out” theflame.)


Nozzle gauge

Checking oil pressure

• If air is found, perform pump tests todetermine why. (Chapter 3)

4. Check air settings—adjust asnecessary.

E. Motor does not start

1. The motor might be off on thermaloverload—if there is a reset, press it. Ifthere is no reset, check to see if the motorfeels hot; if it does, give it a few minutes tocool down.

2. If the motor still does not start, thetrouble is in the motor or motor circuit.

3. If the motor has a capacitor, check itbefore you condemn the motor.

#2 No heat—the unit is warm but noheat is circulating.

If the oilburner operates properly but noheat comes from the radiation or ductwork,the problem is with the delivery system.Make sure that all thermostats are set tocall for heat, verify that heat anticipatorsare properly set and:

Hot water system

1. Check for closed hand ormotorized valves.

2. Check that there is sufficientpressure in the system.

3. Check that the circulator is operatingproperly.

4. Check the flow control valve.

5. Check that the system is notair bound.

6. Check that the high limitis set properly.

7. Check that the reverse aquastat is setproperly.

Warm air system

1. Check that the fan-limit control isset properly.

2. Check that all dampers are open.

3. Check that air filters are clean.

4. Check to see if the bloweris operating:

• If it is, check the drive belt.

• If it is not, check the motor.

Steam system

1. Check the water level—too muchwater in the system will preventsteam from rising.

2. Check for closed hand or motorizedvalves.

3. Check the electrical circuits formotorized valves.

4. Check the main vents.

5. Check the pressuretrol setting.

#3 Insufficient heat—the burner isoperating but the house is much coolerthan the thermostat setting

Sometimes this occurs because it ismuch colder than normal and the house justcannot “keep up”with the outsidetemperature and/orthe system (boiler,furnace, piping,radiation,ductwork) mightbe undersized.



The best Service Techniciansdevelop standard troubleshoot-ing routines. They go from step

to step until they find and correctthe cause of the problem.

1. Thermostat stuck, set too high,improperly located or defective.

2. Limit control defective orset too high.

3. Flow control valve stuck.

4. Motorized valve stuck.

#5 No hot waterTroubleshooting a “no hot water” call

with an oil-fired water heater is basicallythe same as troubleshooting a no heat call;you check the burner and the limit control.When the hot water comes from a domestichot water coil or storage tank, you should:

1. Check the aquastat settings.

2. Check to be sure the water level inthe boiler is above the coil.

3. Check the mixing valve.

4. If there’s a storage tank installed:

• Check the control setting.

• Check the circulator.

• If the tank seems to be full of hotwater but the water coming from the hottapping is cool, check the dip tube on theinlet to the tank.

#6 Water leakDepending on the severity of the leak,

this can be a minor inconvenience or amajor problem.

1. USE CAUTION! Never work onelectrical components while they are wet orwhen you’re standing on wet floors.

Helpful hint—Treat all electrical circuitsas if they were energized even when you’resure they aren’t.



Your job is like adetective’s—youmust figure outwhat happened,

why it happened,how to fix it

and how to keepit from happening

again.

Other causesfor insufficient heat:A. Burner trouble

1. The burner might be under-fired. Make sure that the burner’sfiring rate is properly set for theboiler or furnace.

B. Control circuit

1. Check the heat anticipator settings.

2. Check that the thermostat is properlylocated. Thermostats are affected by theheat generated by lamps, appliances orfireplaces and should not be located nearany heat source.

3. Check that the limit controls andreverse acting aquastats are properly set.

C. Heating systems

1. Check to be sure that the steam ventsare operating properly.

2. Check that pipes and/or ductwork areproperly insulated.

3. Check that airflow through air filters,radiators, or baseboard is not obstructed bydust, closed air dampers, carpet, furnitureor curtains.

4. Check that the water level is adequatein steam systems.

5. Check that hot water systems are notair bound.

6. Check that blowers and their pulleysand belts are functioning properly.

.

#4 Too much heatWhen the customer complains of too

much heat the most likely causes are:

2. If a relief valve is leaking:

Steam system—check the steam gaugeand the pressuretrol. Remember thatresidential steam systems should operate ata maximum of 2 PSI and steam reliefvalves open at 15 PSI. If the relief valveopens, it is likely either the valve or thepressuretrol is malfunctioning.

Hot water system—a number of thingscan cause the relief valve to open on a hotwater system:

• A full expansion tank.

• A bad diaphragm on a pressurizedexpansion tank.

• A malfunctioning or improperly setaquastat.

• A misadjusted or malfunctioningpressure-reducing valve.

• A leaking domestic hot water coil.

• A malfunctioning relief valve.

Water heater—check the aquastat andthe domestic hot water pressure.

Helpful hint—many municipalitiesrequire the installation of backflow preven-tion devices that can cause heating systemrelief valves to open. Often the only way tostop the valve from opening is to install adomestic water expansion tank.

3. Circulator flange gaskets can leak.Tightening the flange may stop the leak butit is usually better to replace the gasketsonce they start leaking.

4. Older style circulators often had aseparate bearing assembly that would leakwater from a weep hole when they becamedefective. With this type of leak, you caneither change the bearing assembly orreplace the entire circulator with a modernwater lubricated model.

5. If the boiler itself is leaking, it isusually beyond repair. Turn off the electricpower and the water supply to the unit,drain the remaining water from the systemand contact your supervisor for instruc-tions.

Helpful hint—Customers often complainof water leaks during rainstorms. These“water leaks” are sometimes caused byrainwater coming down the chimney andleaking onto the floor.

Remember that each gallon of oil burnedcreates a gallon of water in the combustiongases. If the boiler water temperature dropsbelow 130 degrees, the water in thecombustion gases will condense in the heatexchanger, mimicking a water leak.

#7 Oil leaksOil leaks are a serious concern because

they can lead to significant damage. Yourapproach to these calls will depend on theseverity of the leak.

Minor leaks typically occur at:

1. Brass fittings: If the system hascompression fittings, they should bereplaced with flare fittings. If a flare fittingis leaking, turn off the oil supply then


Remember that each gallon of oilburned creates a gallon of water in thecombustion gases. If the boiler water

temperature drops below 130 degrees,the water in the combustion gases will

condense in the heat exchanger,mimicking a water leak.




Compression fitting

Flair fitting

a minor leak, put a magnet patch on it andcall you supervisor for instructions.

6. Oil lines: oil lines, especially thosein contact with concrete, can develop holesand leak. Do NOT cut out the leakingsection and replace it with a new piece ofcopper. When a leak develops, replace theline from the tank to the burner; if the lineis buried in or contacts concrete, installcoated copper tubing or install the line insecondary containment.

If you encounter a more serious leak, tryto stop the flow of oil, shut off any sumppumps in thearea and closeoff floordrains andany access togroundwater.Contact yourofficeimmediatelyand spreadabsorbent while youwait for help to arrive.

#8 Odors, smoke, or sootSeveral different problems can cause

these troubles, among them are:

1. Delayed ignition

2. Combustion problems

3. Dirty or defective chimney or flue

4. Insufficient air in boiler room

5. Air leaks in the boiler

6. Defective heat exchanger

7. House fan sucking air down thechimney

#9 NoiseThese calls are often frustrating because

the noise can be intermittent. When youarrive, the noise may have stopped and youwill have to run the burner through several

disassemble and inspectthe flare. If the flare looksto be in good conditionreconnect it, tighten it,clean it with an absorbentrag and run the burner.After several minutesinspect the fitting closely,if there’s any evidence ofa leak cut out the flare, re-

flare the copper, reconnect it and keepchecking until you’re sure the leak has beenstopped.

2. Malleable fittings: If you find aleak at a malleable fitting, inspect it closelybefore taking it apart. If the leak appears tobe coming from the area where the fittingis threaded, disassemble it, clean it, applypipe joint compound and reconnect it.

If the leak appears to be coming from acrack or sand hole, replace the fitting.

3. Fuel unit: If a leak appears to becoming from a fuel unit, check that all ofthe fittings, plugs and bolts that hold thecover are tight. If the leak continues, checkthe gasket; if it is leaking, replace it. If thepump is still leaking, replace it.

4. Oilburner: Most burners have a“weep hole” in the bottom that allows oilto drain from the housing. If you find sucha leak check:

• The pump seal.

• The nozzle adaptor.

• For an after-drip from the nozzle.

5. Tanks: Minor leaks at tanks oftenappear as drips or wet spots. If the tank has

Staining indicatesa leak in oil linecoming throughconcrete floor



cycles and raise all the thermostats to get itto start. Some heating system noisesoriginate in the area near the heatingsystem, but can only be heard in the livingarea.

Noises can come from:

• Worn pump gears

• High vacuum

• Air in oil line

• Oil lines in contact with each other,boiler/furnace jacket, beams, or otheritems

• Air in a hot water heating system

• Electrical circuit—hum from relays,transformers, motors, etc

• Improper control settings (too muchpressure or temperature)

• Circulators

• Blowers

• Zone valves

• Loose covers on controls

• Water pipes

• Heating pipes and baseboard

• Chimneys

ConclusionMuch of what you learn about trouble-

shooting will be due to your on-the-jobexperiences. We hope that you will remem-ber the “5 Whys” and always look beyondthe symptoms for the cause.

A final piece of troubleshooting advice:“Listen, look and think before you rip, tearand destroy.”

.

The following Troubleshooting chartswere provided by Beckett Corp. andRiello. We thank them for allowing

us to share them with you.


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