HVAC Gas Heat Certification Exam
Questions and Answers 2025
A gas furnace is to be installed in a garage. The national standards require
that the burners and ignition sources must be located above the floor -
-18 inches
A good description of how a bi-metal fan switch operates the blower motor on
a gas furnace is - -Temperature on- temperature off
Redundant gas valves used on gas furnaces have - -Dual gas shut off
seats
Burning one cubic foot of liquefied petroleum gas completely will produce
approximately BTUs - -2000 - 2500
LP gas has a specific gravity of - -1.5 - 2.0
What is the purpose of a spoiler screw located on a burner, or
adjustable-shutters? - -Mix primary air and gas
Furnace limit switches are wired in series with the - -Gas 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 - -3 feet
A technician determines that a natural gas furnace has a defective heat
exchanger. The technician should - -Inform the homeowner and turn
the gas off
A natural gas furnace usually requires gas pressure at the manifold and
burners - -3.5 in. W.C.
The vent system for a condensing furnace is classified as by the
National Field Gas Code. - -Category IV
Type B vent pipe must be kept at least from combustible materials -
-One inch
Typical condensing furnaces have an AFUE rating of at least - -90%
, 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 - -Point it down
The reason heating thermostat have anticipated is to - -Reduce lag
The typical flue gas temperature of a Category III furnace is - -280°F -
300°F
Natural gas primary consists of - -Methane
Burning one cubic foot of natural gas will produce approximately BTU's
- -900~1,100
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 - -Increase fan speed
A BTU is the amount of heat required to raise the temperature of one pound of
water - -One degree Fahrenheit
Natural gas piping must be sized to prevent excessive pressure drops. The
maximum pressure drop allowance is approximately - -.5 in. W.C.
Gas piping must be installed with a pitch of - -1/4" per 15' run
Pipe joint compound should be applied to - -Male threads completely
A technician is installing a copper elbow on LP gas line; what should be used -
-95/5 solder
To burn one cubic foot of Natural Gas completely, at least of
combustion air must be available - -15 cu ft.
The ignition temperature of Natural Gas is - -1100°F - 1200°F
Air that is mixes with Natural Gas in the burner is called - -Primary air
Questions and Answers 2025
A gas furnace is to be installed in a garage. The national standards require
that the burners and ignition sources must be located above the floor -
-18 inches
A good description of how a bi-metal fan switch operates the blower motor on
a gas furnace is - -Temperature on- temperature off
Redundant gas valves used on gas furnaces have - -Dual gas shut off
seats
Burning one cubic foot of liquefied petroleum gas completely will produce
approximately BTUs - -2000 - 2500
LP gas has a specific gravity of - -1.5 - 2.0
What is the purpose of a spoiler screw located on a burner, or
adjustable-shutters? - -Mix primary air and gas
Furnace limit switches are wired in series with the - -Gas 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 - -3 feet
A technician determines that a natural gas furnace has a defective heat
exchanger. The technician should - -Inform the homeowner and turn
the gas off
A natural gas furnace usually requires gas pressure at the manifold and
burners - -3.5 in. W.C.
The vent system for a condensing furnace is classified as by the
National Field Gas Code. - -Category IV
Type B vent pipe must be kept at least from combustible materials -
-One inch
Typical condensing furnaces have an AFUE rating of at least - -90%
, 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 - -Point it down
The reason heating thermostat have anticipated is to - -Reduce lag
The typical flue gas temperature of a Category III furnace is - -280°F -
300°F
Natural gas primary consists of - -Methane
Burning one cubic foot of natural gas will produce approximately BTU's
- -900~1,100
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 - -Increase fan speed
A BTU is the amount of heat required to raise the temperature of one pound of
water - -One degree Fahrenheit
Natural gas piping must be sized to prevent excessive pressure drops. The
maximum pressure drop allowance is approximately - -.5 in. W.C.
Gas piping must be installed with a pitch of - -1/4" per 15' run
Pipe joint compound should be applied to - -Male threads completely
A technician is installing a copper elbow on LP gas line; what should be used -
-95/5 solder
To burn one cubic foot of Natural Gas completely, at least of
combustion air must be available - -15 cu ft.
The ignition temperature of Natural Gas is - -1100°F - 1200°F
Air that is mixes with Natural Gas in the burner is called - -Primary air
