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Air SolutionsHeating & Air Conditioning Inc.


Technical Exam for New Applicants

Preliminary Applicant - Technical Proficiency Exam 1


Pre-employment Technical Exam

Directions: Please answer the questions to the best of your ability. There are questions of various types, some essay, some multiple choice, and some true-false. The exam starts with basic knowledge and moves into technical proficiency. You have four hours to complete the exam. If you have any questions, please feel free to ask.

1. What is a BTU? British Thermal Unit

2. How many BTU’s are there in a nominal ton of cooling? 12, 000 BTU’s

3. Air Conditioning Systems involve five major components: A Thermostat, A Condenser, A Compressor, An Evaporator, and an Expansion Device. Using the correct terminology, describe how a residential air conditioning system operates? A thermostats controls the system, the condenser discharges heat, the compressor compresses refrigerant, the evaporator absorbs heat, the expansion device meters the refrigerant.

4. Refrigeration is based on the principles of evaporation and condensation. Please explain these principles and how they relate to heat transfer?

5. How is the furnace utilized when there is a call for air conditioning? The furnace supplies the condenser unit with 24V, and the furnace blower is utilized to distribute the conditioned air.

6. Please explain how a heat pump system operates? Opposite of a air conditioner, the outdoor coil absorbs heat, and the indoor coil discharges heat.

7. What makes a heat pump different than an air conditioner? A reversing valve, accumulator and a defrost control.

8. What does the term CFM mean? Cubic Feet Per Minute, used to measure air flow.

9. Why do we need water drains on Air Conditioners? To remove moisture from the evaporator pan.

10. Why is airflow capacity critical to an air conditioners operation? To allow the evaporator to absorb heat, and cause the refrigerant to change from a liquid to a vapor.

11. What methods can heat be transferred? Conduction, Convection and Radiation.

12. Use the following component terms to describe the operating cycle of a natural gas furnace. Thermostat, Gas Valve, Heat Exchanger, Ignition Device, Blower, and Fan & Limit Control? The thermostat calls for heat, the ignition device ignites the gas, as the gas valve opens, as the heat exchanger begins to heat up, the fan control energizes the blower fan to distribute the heat, In case of blower failure the limit control will de-energize the gas valve.



13. What is the difference between combustion air and cold air return? Combustion air is outdoor air supplied to the appliance room. The cold return air supplies the furnace with air to be heated or cooled.

14. What does AFUE stand for? Annual Fuel Utilization Efficiency

15. What are the average flue temperatures of the following furnace types:

60% AFUE__________________ 80 %AFU________________ 93% AFUE______________

16. Which furnace AFUE Range uses PVC pipe and why? 90%+ High efficiency uses PVC venting as it is more efficient than a metal lined chimney.

17. Which furnace AFUE range uses metal flue pipe and an inducer fan system? 80% Mid efficiency

18. What is the difference between a furnace and a boiler? A furnace uses a duct system to distribute heated air, a boiler uses radiators to distribute heated liquid.

19. Can air conditioning be added to a boiler system? Please explain? No, there is no indoor blower on a boiler system to distribute conditioned air.

20. What does a thermostat do? It controls the heating and cooling system, by monitoring the indoor temperature and set point.

21. What are the differences between a mechanical thermostat and an electronic set-back thermostat? A mechanical thermostat contains mercury and a heat anticipator, and electronic thermostat is digital and allows for programmed temperature set points.

22. What does a humidifier do and how and when does it operates? A humidifier uses the hot air from the heating cycle to evaporate the water supply to maintain a relative humidity between 30-50%. It is used in the heating mode only.

23. How does a media filter work? Return air that enters the system is first filtered through a media filter which collects any dust or debris that may otherwise get clogged into the blower, secondary heat exchanger or evaporator coil.

24. How does an electronic filter work? The electronic filter is supplied with 120V or 24V and will collect any dust or particles that travel through it.



25. What does an air purification ultra violet germicidal light do and how does it operate?

26. What is a HEPA filter system and how does it operate?

27. How do high efficiency furnaces (above 90 % AFUE) solve combustion air problems? Direct vent applications bring combustion air directly into the furnace.

28. What is the condition called in a home when you see a black pattern around the perimeter of a home’s interior walls (shows up on carpeting), what causes this condition, and how do you remedy the condition?

29. Describe the steps you would use to wire the electrical power to a replacement outdoor condensing unit that will meet the national and local wiring codes?

30. Explain the differences between a single wall vent pipe and a double wall vent pipe? Single wall vent pipe (C vent) has only one layer of metal, which requires a greater clearance to combustible material (6”). Double wall vent pipe (B vent) contains 2 layers of metal, which allows for a lower clearance to combustible material. (1”).

31. What do you recommend for a furnace that is vented into a masonry chimney? That a chimney liner be installed.

32. Name the circumstances you may need to add additional refrigerant to an air conditioning system? A longer line set then the unit is designed for, or a refrigerant leak which has been repaired.

33. Describe the proper procedures for reclaiming refrigerant from an existing system? Attach the low and high side hoses to the outdoor unit, attach the manifold hose to the recovery unit, and attach the recovery hose to the recovery cylinder. Begin recovering liquid refrigerant, then vapor, then close the manifold gauges and purge the recovery unit into the recovery cylinder.

34. What heating and air conditioning equipment may require a drain to be installed? All high efficiency heating equipment (Condensing) and all air conditioning equipment.

35. If there is no convenient floor drain, what can you do? Install a condensate pump.

36. Why would it be necessary to relocate a thermostat? To install 5 wires, or to remedy a poor location for detecting accurate temperatures.

37. Describe a good location for a thermostat and why? The main floor living area. You will get a more accurate average temperature.



38. What could happen if you added another major natural gas appliance such as a fireplace insert, to the existing gas line? Either unit could become under fired, due to insufficient gas supply.

39. What is the solution to an undersized gas supply line? Replace the gas line with a larger diameter gas line.

40. What is a potential relay and where is it used? It is a relay that is de energized with the increase of EMF from a compressor, used in air conditioning systems.

41. What type of tool would you use to test a capacitor? A multi meter capable of measuring micro farads.

42. What is meant by the phrase, Locked Rotor Amps?

43. When referring to the low voltage wiring on a thermostat what do the following letters designate:

R____24V Hot_________W_____Heating_____Y____A/C_______G_______Fan______T_____________

44. Why do you use a time delay relay in the control circuit of a residential condensing unit? To prevent compressor cycling.

45. How many wires are used in a 120 volt power supply and name them? 3. Line, Neutral and Ground.

46. What does the term temperature rise mean? The temperature difference between the supply air and return air.

47. What is the most common manifold gas pressure setting required on a standing pilot residential gas furnace? 3.5” wc. Natural gas, or 11” wc. Propane.

48. What purpose does the limit control serve in a furnace? To prevent overheating should the indoor blower fail.

49. When clocking a gas meter, what are you determining? The input firing rate of the appliance.

50. What purpose does an isolation relay serve in a gas furnace that uses electronic ignition? To prevent 24V from leaking from the thermostat to the furnace, without a demand for heat.



51. Why is an air-proving switch used on gas furnaces that utilize power vent systems? To prove the venting and drainage system are unobstructed.

52. What does super-heat refer too? The difference between the suction saturation temperature and suction line temperature. Superheat is defined as the difference between the temperature at which the refrigerant boils at the given pressure in the evaporator, and the temperature of the refrigerant gas as it leaves the evaporator.

53. What are the two primary causes of high head pressure in a refrigeration system? Excessive load (high ambient), refrigerant overcharge, plugged outdoor condenser coil.

54. What is a TEV and where is it found in a home comfort system? Thermal expansion valve, found inside at the evaporator, mounted on the suction line. Used to meter refrigerant.

55. Where is the filter drier and what does it do? Absorbs moisture in a refrigeration system. Installed on the liquid line.

56. How would you test the valves of a hermetic compressor in an air conditioner?

57. How would you determine if there was an internal electrical problem on a hermetic compressor? Test the start, common and run windings.

58. Name three areas of good customer service?

59. What do you consider to be your most important tool out of the following list?

Manifold Gauges Volt-Ohm Meter Your Mouth Micro-amp Meter Leak Detector ?

60. What is the purpose of the crank-case heater in an air conditioning system? Keep the compressor warm to prevent liquid migration.

61. You wish to identify start, run, and common terminals on a new single phase compressor by measuring resistances. From terminal X to terminals Y, you read 1 ohm, from terminal Y to terminal Z you read 5 ohms; and from terminal X to terminal Z you read 4 ohms. On the basis of this data, which one of the following identification schemes is correct?

a. X= Start Y = Run Z = CommonPreliminary Applicant - Technical Proficiency Exam 6


b. X= Run Y = Common Z= Start

c. X = Common Y = Run Z = Start

d. X= Common Y = Start Z = Run

62. If a 220 volt source is applied to a load with a resistance of 100 ohms, how much current will flow in the circuit?

a. 220 amperes

b. .45 amps

c. 2.2 amps

d. 45 amperes

63. When you are testing a capacitor with an ohmmeter, the meters needle goes to the low resistance end of the scale and then slowly returns to the high resistance end. Which of the following indicates the most probable condition of the capacitor?

a. Bad

b. Shorted

c. Good

d. Open

64. During a preventative maintenance check-up, you remove the indoor blower access panel to check the blower motor current and read 3.6 amps. The manufacturers data plate on the motor indicates 2.9 full load amps. Which one of the following would probably account for this finding?

a. The blower wheel is too small

b. The access panel needs to be reinstalled

c. The fan capacitor is open

d. The voltage is too high

65. A temporary capacitance boost to start a single compressor should be applied:

a. Directly across the R and C terminals on the compressor.b. Directly across the R and S terminal on the compressor



c. Directly across the S and C terminals on the compressord. Directly across the existing run capacitor compressor connections.

66. Resistance is measured in:

a. Amperesb. Wattsc. Ohmsd. Volts

67. In an electrical circuit, the potential difference measured between to points in a circuit is called:

a. Amperageb. Resistancec. Loadd. Voltage

68. When additional loads are added to a parallel circuit, the current drawn from the power supply _____________

a. Increases

b. Decreases

69. When capacitors are wired in parallel, the equivalent microfarad capacitance value is:

a. increasedb. decreasedc. divided by twod. different for run and start capacitors

70. Power is measured in:

a. Wattsb. Voltsc. Ohmsd. Amperes

71. All three phase motors generally have _____________starting torque?

a. Highb. Lowc. Mediumd. None

72. The run capacitor will be electrically connected to the compressor motor:

a. Terminal R & CPreliminary Applicant - Technical Proficiency Exam 8


b. Terminal R & Sc. Terminals S & Cd. Terminals 2 & 5 on the potential relay

73. Which response best represents the direction of refrigerant flow in an operating cooling system?

a. Evaporator coil, thermal expansion valve, and condenser coilb. Condenser coil, evaporator coil, and thermal expansion valvec. Condenser coil, thermal expansion valve and evaporator coild. Thermal expansion valve, condenser coil , and evaporator coil

74. Hot air will hold ______ moisture than cold air.

a. Moreb. Less

75. A metering device ______ the pressure of a refrigerant.

a. Reducesb. Increases

76. The generally accepted superheat range for a residential air conditioning expansion valves is:

a. 3 to 5 degreesb. 8 to 15 degreesc. 18 to 20 degreesd. 30 to 40 degrees

77. True or False? An increased load on the evaporator coil of an operating air conditioning unit will cause an increase in the suction pressure.

a. Trueb. False

78. True or False? The cooling anticipator has current flowing through it when the thermostat is:

a. Callingb. Satisfied

79. True or False? Compressor start windings have more resistance than the run windings.

a. True

b. False

80. If an evaporator is located above the compressor, the possibility is high for compressor damage due to:

a. Oil migrating to the compressor during the running cycle



b. Liquid refrigerant draining to the compressor during the off cycle.

c. Excessive modulation of the expansion valve occurring during shutdown.

d. Excessive increase in suction-gas pressure during the off cycle.

81. Heat transfer in a cooling system

a. only takes place in the condenser coilb. only occurs when the thermostat is satisfiedc. only takes place in the evaporator coild. only occurs from a high temperature region to a low temperature region

82. The most accurate method of charging an air conditioner is by:

a. the approach methodb. weighing in the chargec. use of refrigeration gaugesd. temperature split across the indoor coil

83. True or False? Slugging the compressor with liquid refrigerant is the primary cause of broken compressor valves.

a. Trueb. False

84. A clogged distributor tube in an evaporator coil can be detected by:

a. Measuring the superheat at the compressorb. Determining which circuit of the coil I warmer than the restc. Checking the suction accumulator for an accumulation of oild. Checking the liquid sight glass for bubbles

85. At 240 volts the amperage of each 5 KW heat element in an electric warm air furnace is approximately?

a. 5 ampsb. 10 ampsc. 20 ampsd. 40 amps

86. True or False? You should not make a high limit check on an electric warm air furnace.

a. True

b. False

87. The electric heat elements in an electric furnace cycle on and off in this order.

a. 1, 2, and 3 on, 1, 2, and 3 offb. 1, 2, and 3 on, 3, 2, and 1 offc. 3, 2, and 1 on, 3, 2, and 1 off



d. 3, 2, and 1 on, 1, 2, and 3 off

88. An electric furnace is controlled by a single stage thermostat. On a call for heat, all connected circuits function properly; however, the heat rise across the furnace is much lower than the design requirement. Which one of the following actions should the technician take to correct this problem?

a. Install a two stage thermostat.b. Reduce air flow through the furnace.c. Increase air flow through the furnace.d. Replace the dirty filter in the return air.

89. The Btu output of an electric resistance heater at rated voltage may be determined by multiplying the wattage by:

a. 4.31

b. 1.08

c. 3.413

d. 3.1416

90. True or False: Always use high speed for cooling and the low speed for heating on a direct drive blower motor in an electric furnace.

a. Trueb. False

91. A multi-stage electric furnace operates only on the first bank of heaters, even though you have just turned the thermostat all the way up. Which of the following is a possible cause for this condition?

a. The second-stage heat anticipator is improperly adjustedb. The time delay sequencer may not have been energized long enough to bring on additional stagesc. The outdoor thermostat is in the closed positiond. The thermostat may be improperly located

92. While performing a preventive maintenance check on an electric furnace, you need to determine the total kilowatt input to the furnace (the data plate is missing). Which of the following instruments would you use to determine the kilowatt input of the furnace?

a. A voltmeter and a thermostatb. An ohmmeter and a voltmeterc. An ohmmeter and a ammeterd. An ammeter and a voltmeter

93. An electric furnace has four (4) 5 KW heating elements that are rated at 240 volts. The available voltage at the job site to operate the furnace is 208 volts. What effect will this have on the Btu output of the furnace.

a. It will not reduce the Btu outputb. There will be no reduction of Btu output if the elements are connected in seriesc. There will be no reduction of Btu output if the elements are connected in paralleld. It will reduce the Btu output of the furnace

94. With 240 volt, 60 Hz single phase power, a 5 KW electric heating element will draw how many amps and produce how many Btu’s.



a. 10.8 amperes, and 9,250 Btub. 15.9 amperes, and 19,576 Btuc. 20.8 amperes, and 17,080 Btud. 20.8 amperes, and 14,450 Btu

95. Knowing the temperature rise across the electric furnace, the supplied voltage to the furnace and the current draw (amperage) of the furnace, what can be determined?

a. Combustion Efficiencyb. S.E.E.R.c. Airflow Volume (CFM)d. A.F.U.E.

96. True or False? An electric furnace is generally considered to be 100 % energy efficient.

a. Trueb. False

97. In an atmospheric gas burner, the presence of a yellow or orange flame indicates:

a. Too much primary airb. The burner orifice is too smallc. The manifold gas pressure is too highd. Not enough primary air

98. The secondary or auxiliary limit switch is located:

a. in the blower compartment of an upflow furnaceb. in the heat exchanger areac. in the stack controld. in the blower compartment of a down flow furnace

99. Temperature rise on a furnace is defined as:

a. Temperature of supply air plus temperature of return airb. Temperature of outdoor air plus temperature of condenser coilc. Temperature of indoor air minus temperature of outdoor aird. Temperature of supply air minus temperature of return air

100. On a spark ignition gas furnace, the spark ignites the pilot flame but continues to spark and the main gas valve will not open. Why?

a. flame rectification current is low or missingb. thermostat anticipation current too lowc. gas valve stuck open d. limit switch open

101. On a service call, you notice the gas flame ignites in the venturi of the burner. What is probably the cause?

a. gas pressure too highb. too much secondary airc. gas pressure too low



d. too much primary air

102. Flame impingement produces incomplete combustion in a natural gas furnace because:

a. the flame is cooled below its ignition temperatureb. the secondary air is reducedc. the fuel supply is decreasedd. the gas pressure is too high

103. The heat anticipator is in series with the main gas valve on a natural gas furnace, and therefore:

a. is energized when the thermostat is satisfiedb. anticipates when the thermostat will call for heatc. blows the fuse when the thermostat calls for heatd. is energized when the thermostat calls for heat

104. Some spark ignition gas furnaces use flame rectification to prove the pilot flame. To check the micro-amp current value the pilot flame, connect the micro-amp meter in _________ with the pilot sensor.

a. Seriesb. Parallel

105. In a condensing furnace, the burners cycle intermittently on the inducer-proving pressure switch. What is a possible cause of the problem?

a. Blockage or restriction in the combustion air or vent piping.b. Flame rollout switch open.c. Inducer motor open..d. Open contacts in the pressure switch.

106. Which of these components provide the same function? (Bullshit question)

a. fan switch and limit switchb. fan relay and limit switchc. fusible link and flame rollout switchd. inducer motor and vent damper

107. What is a possible consequence of too low a temperature rise in a gas-fired condensing furnace?

a. No adverse consequences.b. Furnace may overheat.c. Primary heat exchanger may corrode.d. Condensation may form in the secondary heat exchanger.

108. Flame rectification is a process by which:

a. the burner flames are rectified for quieter operation.b. The pilot flame is rectified for quieter operation.c. An electrical current passes through a flame.



d. A voltage is generated by a flame.

109. In a heat pump defrost cycle, the following components operate as indicated:

a. Outdoor fan – off; reversing valve – heating position; indoor fan – on.b. Outdoor fan – on; reversing valve – cooling position; indoor fan – offc. Outdoor fan – off; reversing valve – cooling position; indoor fan – offd. Outdoor fan – off; reversing valve – cooling position; indoor fan – on; auxiliary heat – on

110. The term “balance point” for a heat pump refers to the point where the:

a. heating capacity of the heat pump equals the heat loss of the structureb. heating capacity and cooling capacity of the heat pump are equalc. suction pressure and head pressure have equalized so the compressor can startd. amount of heat picked up by the outdoor coil equals the heat rejected by the indoor coil

111. Abnormally high heat pump suction pressure at the compressor in the heating and cooling cycles could indicate:

a. bad compressor valves or an internal leak in the reversing valveb. and external leak in the reversing valve or an undercharged systemc. a restricted accumulatord. a stuck reversing valve

112. Refrigerant in a heat pump will condense in:

a. the outdoor coil in the heating cycle and the indoor coil in the cooling cycleb. both the indoor and outdoor coils any time the compressor is runningc. the outdoor coil in the cooling cycle and the indoor coil in the heating cycled. the outdoor coil in both the heating and the cooling cycle

113. Refrigerant migration to the compressor during the off cycle can be prevented by the use of:

a. a reversing valve relay b. a crankcase heaterc. a de-ice controld. a check valve

114. In the heating season, if the heat pump’s indoor fan failed to operate while the thermostat was calling for heat, what would happen?

a. the unit would operate in the cooling modeb. the high pressure switch would openc. the low pressure switch would opend. the indoor coil would ice up

115. During the cooling cycle, in a heat pump with a piston-type metering device, the outdoor metering device will be in the:

a. bypass positionb. front-seated position



c. neutral positiond. metering position

116. In an air-to-air heat pump, the refrigerant will condense in:

a. the outdoor coil in the cooling cycle and the indoor coil in the heating cycleb. the outdoor coil in the heating and cooling cyclesc. both the indoor and outdoor coils anytime the compressor is runningd. the outdoor coil in the heating cycle and the indoor coil in the cooling cycle

117. On a routine heat pump service call, you note there is low superheat, high suction pressure and excessive sweating of the compressor. The unit is equipped with a TEV. The most likely problem is:

a. the power element of the TEV has lost its chargeb. the sensing bulb on the suction line is loosec. the system has a slight overcharge of refrigerantd. the system has an undercharge of refrigerant

118. Which statement best describes heat pump operation?

a. It is too cold to operate a heat pump in Alaska or Canadab. Heat pumps are only economically feasible in the southern parts of the United Statesc. Heat pumps can extract heat from the outdoor air even if the temperature is below zero.d. Heat pumps require no special installation considerations versus an air conditioner.

119. Which statement about heat pump compression ratio is correct?

a. Compression ratio is higher in coolingb. Compression ratio is the same in heating and coolingc. Compression ratio is higher in heatingd. The greater the difference between suction and discharge pressure, the lower the compression ratio.

120. You are called on to change a failed compressor in a heat pump. After you remove the failed compressor you notice it contains almost no oil. Further investigation reveals the accumulator is nearly full of oil. What does this indicate?

a. The compressor discharged its oil into the accumulator.b. The accumulator is too small for the systemc. The system was overcharged with oil.d. The accumulator has an internal blockage.

121. In an air cooled system with capacity control, compressor unloading will cause the :

a. suction pressure to rise and the discharge pressure to fallb. suction pressure to fall and energy consumption to decreasec. suction pressure and discharge pressure to falld. discharge pressure to rise and energy consumption to decrease

122. Which of the following electrical components must a compressor non recycling pump-down circuit contain?

a. Liquid line solenoid valve, high pressure switch, compressor contacts, winding thermostats, and low pressure control



b. Control relay, low pressure switch, auxiliary compressor contacts, liquid line solenoid valve, compressor contactor, and temperature control

c. High pressure control, condenser fan contacts, and compressor contacts control relayd. Compressor winding thermostat, control relay A, condenser fan contacts, and compressor contactor

123. The installation instructions of an air conditioning system call for trapping the suction line when the condenser is installed above the evaporator. Which of the following is the reason for doing this?

a. To keep suction pressure from risingb. To ensure oil return to the compressc. To maintain proper head pressured. To provide for proper condensate drainage

124. On start-up, a newly installed 20 ton packaged roof top air conditioning unit is operating with a very high head pressure. Which one of the following situations is the most likely cause of the problem?

a. The condenser fan motor is running backwardsb. The evaporator motor is not runningc. The system is underchargedd. The expansion valve is stuck open

125. To operate properly, the duct system of a 7.5 ton packaged heat pump should be designed for a nominal airflow of:

a. 1200 cfmb. 3000 cfmc. 4000 cfmd. 7500 cfm

126. A common problem with restaurant units is their location near kitchen exhaust hoods. This could cause high discharge pressure in the cooling mode because the:

a. air filters become pluggedb. evaporator belts slipc. grease plugs the condensate lined. grease plugs the condenser coil

127. A customer requests repair of a packaged rooftop air conditioner that uses R-22. The head pressure is 145 psig and the suction pressure is 120 psig. The compressor is hot; the discharge and suction lines at the compressor are extremely hot. Which of the following is the most likely cause for this malfunction:

a. Restricted refrigerant flowb. Air in high sidec. A defective compressor valved. A low refrigerant charge

128. You make a service call in answer to a complaint of little or no cooling from a roof top air conditioning unit. Upon checking pressures when the unit is running, you read 52 psig on the low side and 190 psig on the high side. The unit uses R-22. Superheat at the compressor is 0 degrees F. The problem most likely occurs because the:



a. evaporator coil is iced upb. unit is full of non-condensable agentsc. unit is underchargedd. unit is overcharged

129. On a delta wound motor, the effective voltage on a 480 volt motor between terminals will be:

a. 208 volts ACb. 240 volts ACc. 277 volts ACd. 480 volts AC

130. In an economizer, an enthalpy control regulates the use of outdoor air on the basis of the air’s;

a. humidity and temperatureb. sensible heatc. latent heatd. return flow temperature

131. A packaged rooftop heat pump you are called to service will not defrost adequately. What is a common reason for this?

a. The time in defrost is too short.b. Wind on the roof is retarding defrost.c. Compressor suction valves are brokend. Condensing coil is too big.

132. One advantage a semi-hermetic (serviceable hermetic) compressor has over a welded hermetic compressor is that:

a. It is usually lighter and more compact.b. The oil can be easily removed and replacedc. It does not require motor protection.d. It does not require a crankcase heater.

133. What percentage of CO2 should be in the flue gas of a properly adjusted oil furnace?

a. 3to 5 %

b. 5 to 8 %c. 8 to 10 %d. 10 to 13 %

134. If you convert a two-line oil system to a one-line system and do not remove the internal bypass plug from the pump, what will result?

a. the furnace will be over fired

b. the furnace will not get enough oilc. the seals in the oil pump will blowd. the primary control will not permit the furnace to operate.

135. A harsh white flame in an oil burner is an indication of?

a. too little air

b. too much airPreliminary Applicant - Technical Proficiency Exam 17


c. too little oil pressured. too much oil pressure

136. The minimum draft over the fire should be?

a. +0.02 water columnb. +0.01 water column c. 0.00 water columnd. –0.01 water column

137. True or False? If you install a larger nozzle in an oil furnace, you must raise the oil pressure to over 100 psig.

a. Trueb. False

138. If an oil furnace is firing and the Cad cell is disconnected, what will happen?

a. burner will shut downb. burner will operate for 30 to 90 seconds, then shut downc. will have no effectd. blower will shut down

139. A high vacuum reading in the oil supply line indicates:

a. the oil tank is fullb. there is no oil in the tankc. a restriction in the oil lined. the oil line has an air leak in it

140. The barometric damper, or draft control in an oil furnace is:

a. a temperature deviceb. a pressure sensitive devicec. a light sensitive deviced. a thermal overload

141. When installing an oil fired heating unit that is located significantly higher than the oil storage tank, the technician should use a:

a. two-stage oil pump and a two-pipe systemb. two-stage oil pump and a single-pipe systemc. singe-stage oil pump and a single-pipe systemd. single-stage oil pump and a two-pipe system

142. True or False? In northern climates where temperatures are consistently below freezing, No. 2 fuel oil is the best choice if the customer has an outdoor fuel storage tank.

a. Trueb. False


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