GAS HEAT ESCO EXAM QUESTIONS &
ANSWERS(RATED A+)
A gas furnace to be installed in a garage. The national standards requires that the
burners and ignition must be located ____ above the floor: - ANSWER18 inches
The vent system for a condensing furnace is classified as ___ by the National Field
Gas Code. - ANSWERCategory IV (4)
Type B vent pipe must be kept at least ____ from combustible materials. -
ANSWERone inch
Typical condensing furnaces have an AFUE rating of at least: - ANSWER90%
You have installed a Category IV two-pipe vent system that terminates through the
roof of the residence. The elbow for the combustion air intake, above the roof,
should...? - ANSWERPoint down
A good description of how a bi-metal fan switch operates the blower motor on a gas
furnace is: - ANSWERTemperature on/ Temperature off
Redundant gas valves used on gas furnaces will shut down if gas pressure exceeds:
- ANSWER13.5 in W.C. (or 1/2 psi)
This is the maximum pressure for gas valve operation
Burning one cubic foot of Liquefied Petroleum gas completely will produce
approximately ____ BTUs. - ANSWER2,000 - 2,500
LP gas has a specific gravity of ...? - ANSWER1.5 - 2.0 ( actual is 1.5 heavier than
air which is 1.0)
What is the purpose of a spoiler screw located on a burner, or adjustable-shutters? -
ANSWERto mix primary air and gas
Furnace limit switches are wired in series with the: - ANSWERGas valve
A technician is using an extension ladder to work on roof top unit. The top of the
ladder should extend _____ beyond the support point. - ANSWER3 feet
A technician determines that a natural gas furnace has a defective heat exchanger.
The technician should: - ANSWERInform the home owner and turn the gas off.
A natural gas furnace usually requires _____ gas pressure AT the manifold and
burners.
What should the inlet pressure be to the manifold? - ANSWER3.5 in WC
inlet- 5-7 in WC
, The reason heating thermostats have anticipators is to: - ANSWERreduce overshoot
The typical fluw gas temperature of a Category III furnace is: - ANSWER280 F - 300
F
The proper chemical name for natural gas is: - ANSWERMethane
Burning one cubic foot of natural gas will produce approximately ___ BTU's. -
ANSWER900-1100
A furnace nameplate specifies a temperature rise of 40 to 70 degrees. Temperature
measurements indicate a rise of 80 degrees. The most appropriate action is to: -
ANSWERincrease fan speed
A BTU is the amount of heat required to raise the temperature of one pound of
water: - ANSWERone degree Fahrenheit
Natural gas piping must be sized to prevent excessive pressure drops. The National
Fuel Gas Code maximum pressure drop allowance is approximately: - ANSWER0.35
in WC
Gas piping must be installed with a pitch of: - ANSWER1/4" per 15' run
Pipe joint compound should be applied to: - ANSWERmale threads less two end
threads
A technician is installing a copper elbow on LP gas line; what should be used? -
ANSWER15% silver solder
To burn one cubic foot of Natural Gas completely, AT LEAST ____ of combustion air
must be available. - ANSWER10 cu ft.
The ignition temperature of Natural Gas is ____ - ANSWER1100 F - 1200 F
Air that is mixed with Natural Gas in the BURNER is called: - ANSWERPrimary Air
What is the volume of flue gas produced from a Natural Gas furnace with a draft
diverter? - ANSWER30 cu ft.
The purpose of a flue baffle is to: - ANSWERincrease heat exchange
The LP gas pressure supplied to the appliance gas valve should be: - ANSWER11-
13 in WC
An installed gas furnace should have a minimum of ____ inches for service access. -
ANSWER24 inches
On a dedicated vent system, a fire stop support plate is located: - ANSWERwhere it
passes through a ceiling
ANSWERS(RATED A+)
A gas furnace to be installed in a garage. The national standards requires that the
burners and ignition must be located ____ above the floor: - ANSWER18 inches
The vent system for a condensing furnace is classified as ___ by the National Field
Gas Code. - ANSWERCategory IV (4)
Type B vent pipe must be kept at least ____ from combustible materials. -
ANSWERone inch
Typical condensing furnaces have an AFUE rating of at least: - ANSWER90%
You have installed a Category IV two-pipe vent system that terminates through the
roof of the residence. The elbow for the combustion air intake, above the roof,
should...? - ANSWERPoint down
A good description of how a bi-metal fan switch operates the blower motor on a gas
furnace is: - ANSWERTemperature on/ Temperature off
Redundant gas valves used on gas furnaces will shut down if gas pressure exceeds:
- ANSWER13.5 in W.C. (or 1/2 psi)
This is the maximum pressure for gas valve operation
Burning one cubic foot of Liquefied Petroleum gas completely will produce
approximately ____ BTUs. - ANSWER2,000 - 2,500
LP gas has a specific gravity of ...? - ANSWER1.5 - 2.0 ( actual is 1.5 heavier than
air which is 1.0)
What is the purpose of a spoiler screw located on a burner, or adjustable-shutters? -
ANSWERto mix primary air and gas
Furnace limit switches are wired in series with the: - ANSWERGas valve
A technician is using an extension ladder to work on roof top unit. The top of the
ladder should extend _____ beyond the support point. - ANSWER3 feet
A technician determines that a natural gas furnace has a defective heat exchanger.
The technician should: - ANSWERInform the home owner and turn the gas off.
A natural gas furnace usually requires _____ gas pressure AT the manifold and
burners.
What should the inlet pressure be to the manifold? - ANSWER3.5 in WC
inlet- 5-7 in WC
, The reason heating thermostats have anticipators is to: - ANSWERreduce overshoot
The typical fluw gas temperature of a Category III furnace is: - ANSWER280 F - 300
F
The proper chemical name for natural gas is: - ANSWERMethane
Burning one cubic foot of natural gas will produce approximately ___ BTU's. -
ANSWER900-1100
A furnace nameplate specifies a temperature rise of 40 to 70 degrees. Temperature
measurements indicate a rise of 80 degrees. The most appropriate action is to: -
ANSWERincrease fan speed
A BTU is the amount of heat required to raise the temperature of one pound of
water: - ANSWERone degree Fahrenheit
Natural gas piping must be sized to prevent excessive pressure drops. The National
Fuel Gas Code maximum pressure drop allowance is approximately: - ANSWER0.35
in WC
Gas piping must be installed with a pitch of: - ANSWER1/4" per 15' run
Pipe joint compound should be applied to: - ANSWERmale threads less two end
threads
A technician is installing a copper elbow on LP gas line; what should be used? -
ANSWER15% silver solder
To burn one cubic foot of Natural Gas completely, AT LEAST ____ of combustion air
must be available. - ANSWER10 cu ft.
The ignition temperature of Natural Gas is ____ - ANSWER1100 F - 1200 F
Air that is mixed with Natural Gas in the BURNER is called: - ANSWERPrimary Air
What is the volume of flue gas produced from a Natural Gas furnace with a draft
diverter? - ANSWER30 cu ft.
The purpose of a flue baffle is to: - ANSWERincrease heat exchange
The LP gas pressure supplied to the appliance gas valve should be: - ANSWER11-
13 in WC
An installed gas furnace should have a minimum of ____ inches for service access. -
ANSWER24 inches
On a dedicated vent system, a fire stop support plate is located: - ANSWERwhere it
passes through a ceiling
