1|Page
NATE Gas Heat Practice Guide (NEW UPDATED VERSION) LATEST
ACTUAL EXAM QUESTIONS AND CORRECT ANSWERS (VERIFIED
QUESTIONS AND ANSWERS)- GUARANTEED PASS A+ UPDATED 2025
NATE Gas Heating Exam – Practice
Questions
1–10: Safety & Tools
1. Before servicing a gas furnace, you should:
A. Turn on the thermostat
B. Turn off power and gas
C. Remove the air filter only
D. Test the blower
Rationale: Shutting off power and gas prevents fire, explosion, and shock.
2. Which tool is used to measure gas pressure?
A. Multimeter
B. Manifold gauge
C. Thermometer
D. Screwdriver
3. Personal protective equipment for furnace servicing includes:
A. Shorts and gloves
B. Gloves and safety glasses
C. Flip flops
D. T-shirt only
4. A gas leak detector is used to:
A. Measure airflow
2026 2027 GRADED A+
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B. Detect combustible gases
C. Check voltage
D. Test refrigerant
5. What should you do if you smell gas?
A. Light a match
B. Evacuate and ventilate, then call service
C. Ignore it
D. Spray water
6. A lockout/tagout procedure ensures:
A. Faster service
B. Equipment isn’t energized during service
C. Proper thermostat function
D. Air filter replacement
7. Before performing electrical tests, always verify:
A. Power is off
B. Gas valve is open
C. Heat exchanger temperature
D. Thermostat setpoint
8. A voltmeter should be set to a range:
A. Lower than expected reading
B. Higher than expected reading
C. Exactly equal
D. Any range
9. A technician should check for proper combustion air to:
A. Improve airflow
B. Ensure safe, complete combustion
C. Cool the room
D. Increase efficiency
2026 2027 GRADED A+
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10. A furnace cabinet should be:
A. Painted red
B. Secure, accessible, and free of leaks
C. Open to the room
D. Installed in the attic only
11–20: Gas & Combustion Fundamentals
11. Natural gas is mostly:
A. Propane
B. Methane
C. Butane
D. Carbon monoxide
12. Complete combustion produces:
A. Carbon monoxide
B. Carbon dioxide and water
C. Nitrogen
D. Smoke
13. Incomplete combustion produces:
A. CO
B. CO₂
C. H₂O
D. Methane
14. A correct fuel-to-air ratio ensures:
A. Safety and efficiency
B. More noise
C. Lower heat output only
D. Faster fan speed
15. Flue pipes vent:
A. Filtered air
B. Combustion gases
2026 2027 GRADED A+
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C. Cool air
D. Water only
16. AFUE measures:
A. Electrical usage
B. Heating efficiency
C. Furnace weight
D. Gas pressure
17. High flue temperature indicates:
A. Efficient heat transfer
B. Heat loss up the vent
C. Proper combustion
D. Cold air
18. Insufficient combustion air can cause:
A. Flame rollout
B. Carbon monoxide buildup
C. Cooler air
D. Faster fan
19. The flame sensor stops gas if:
A. The thermostat is off
B. Flame is absent
C. Fan is running
D. Air filter is clean
20. Heat exchangers transfer:
A. Electrical energy
B. Heat to air safely
C. Fuel
D. Cool air
2026 2027 GRADED A+
NATE Gas Heat Practice Guide (NEW UPDATED VERSION) LATEST
ACTUAL EXAM QUESTIONS AND CORRECT ANSWERS (VERIFIED
QUESTIONS AND ANSWERS)- GUARANTEED PASS A+ UPDATED 2025
NATE Gas Heating Exam – Practice
Questions
1–10: Safety & Tools
1. Before servicing a gas furnace, you should:
A. Turn on the thermostat
B. Turn off power and gas
C. Remove the air filter only
D. Test the blower
Rationale: Shutting off power and gas prevents fire, explosion, and shock.
2. Which tool is used to measure gas pressure?
A. Multimeter
B. Manifold gauge
C. Thermometer
D. Screwdriver
3. Personal protective equipment for furnace servicing includes:
A. Shorts and gloves
B. Gloves and safety glasses
C. Flip flops
D. T-shirt only
4. A gas leak detector is used to:
A. Measure airflow
2026 2027 GRADED A+
,2|Page
B. Detect combustible gases
C. Check voltage
D. Test refrigerant
5. What should you do if you smell gas?
A. Light a match
B. Evacuate and ventilate, then call service
C. Ignore it
D. Spray water
6. A lockout/tagout procedure ensures:
A. Faster service
B. Equipment isn’t energized during service
C. Proper thermostat function
D. Air filter replacement
7. Before performing electrical tests, always verify:
A. Power is off
B. Gas valve is open
C. Heat exchanger temperature
D. Thermostat setpoint
8. A voltmeter should be set to a range:
A. Lower than expected reading
B. Higher than expected reading
C. Exactly equal
D. Any range
9. A technician should check for proper combustion air to:
A. Improve airflow
B. Ensure safe, complete combustion
C. Cool the room
D. Increase efficiency
2026 2027 GRADED A+
,3|Page
10. A furnace cabinet should be:
A. Painted red
B. Secure, accessible, and free of leaks
C. Open to the room
D. Installed in the attic only
11–20: Gas & Combustion Fundamentals
11. Natural gas is mostly:
A. Propane
B. Methane
C. Butane
D. Carbon monoxide
12. Complete combustion produces:
A. Carbon monoxide
B. Carbon dioxide and water
C. Nitrogen
D. Smoke
13. Incomplete combustion produces:
A. CO
B. CO₂
C. H₂O
D. Methane
14. A correct fuel-to-air ratio ensures:
A. Safety and efficiency
B. More noise
C. Lower heat output only
D. Faster fan speed
15. Flue pipes vent:
A. Filtered air
B. Combustion gases
2026 2027 GRADED A+
, 4|Page
C. Cool air
D. Water only
16. AFUE measures:
A. Electrical usage
B. Heating efficiency
C. Furnace weight
D. Gas pressure
17. High flue temperature indicates:
A. Efficient heat transfer
B. Heat loss up the vent
C. Proper combustion
D. Cold air
18. Insufficient combustion air can cause:
A. Flame rollout
B. Carbon monoxide buildup
C. Cooler air
D. Faster fan
19. The flame sensor stops gas if:
A. The thermostat is off
B. Flame is absent
C. Fan is running
D. Air filter is clean
20. Heat exchangers transfer:
A. Electrical energy
B. Heat to air safely
C. Fuel
D. Cool air
2026 2027 GRADED A+
