HVAC Gas Heat Certification Exam Practice Questions
and Correct Answers Graded A+ 2025/2026
1. 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
2. A good description of how a bi-metal fan switch operates the blower motor on a
gas furnace is: Temperature on- temperature ott
3. Redundant gas valves used on gas furnaces have: Dual gas shut ott seats
4. Burning one cubic foot of liquefied petroleum gas completely will produce
approximately BTUs: 2000 - 2500
5. LP gas has a specific gravity of: 1.5 - 2.0
6. What is the purpose of a spoiler screw located on a burner, or adjustable-shut- ters?:
Mix primary air and gas
7. Furnace limit switches are wired in series with the: Gas valve
8. A technician is using an extension ladder to worḳ on roof top unit. The top of the
ladder should extend beyond the support point: 3 feet
9. A technician determines that a natural gas furnace has a defective heat
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, exchanger. The technician should: Inform the homeowner and turn the gas ott
10. A natural gas furnace usually requires gas pressure at the manifold and
burners: 3.5 in. W.C.
11. The vent system for a condensing furnace is classified as by the National
Field Gas Code.: Category IV
12. Type B vent pipe must be ḳept at least from combustible materials: One
inch
13. Typical condensing furnaces have an AFUE rating of at least: 90%
14. You have installed a Category IV two-pipe vent system that terminates
through the roof of the residence. The elbow for the combustion air intaḳe,
above the roof, should: Point it down
15. The reason heating thermostat have anticipated is to: Reduce lag
16. The typical flue gas temperature of a Category III furnace is: 280°F - 300°F
17. Natural gas primary consists of: Methane
18. Burning one cubic foot of natural gas will produce approximately BTU's-
: 900~1,100
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12
and Correct Answers Graded A+ 2025/2026
1. 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
2. A good description of how a bi-metal fan switch operates the blower motor on a
gas furnace is: Temperature on- temperature ott
3. Redundant gas valves used on gas furnaces have: Dual gas shut ott seats
4. Burning one cubic foot of liquefied petroleum gas completely will produce
approximately BTUs: 2000 - 2500
5. LP gas has a specific gravity of: 1.5 - 2.0
6. What is the purpose of a spoiler screw located on a burner, or adjustable-shut- ters?:
Mix primary air and gas
7. Furnace limit switches are wired in series with the: Gas valve
8. A technician is using an extension ladder to worḳ on roof top unit. The top of the
ladder should extend beyond the support point: 3 feet
9. A technician determines that a natural gas furnace has a defective heat
1/
12
, exchanger. The technician should: Inform the homeowner and turn the gas ott
10. A natural gas furnace usually requires gas pressure at the manifold and
burners: 3.5 in. W.C.
11. The vent system for a condensing furnace is classified as by the National
Field Gas Code.: Category IV
12. Type B vent pipe must be ḳept at least from combustible materials: One
inch
13. Typical condensing furnaces have an AFUE rating of at least: 90%
14. You have installed a Category IV two-pipe vent system that terminates
through the roof of the residence. The elbow for the combustion air intaḳe,
above the roof, should: Point it down
15. The reason heating thermostat have anticipated is to: Reduce lag
16. The typical flue gas temperature of a Category III furnace is: 280°F - 300°F
17. Natural gas primary consists of: Methane
18. Burning one cubic foot of natural gas will produce approximately BTU's-
: 900~1,100
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