Page 1 of 161
HVAC CONTRACTOR EXAM QUESTIONS
AND ANSWERS
1. When recovering refrigerant from a system, the technician
must:
a) Vent refrigerant into the atmosphere if below 5 lbs
b) Use a recovery cylinder that is over 80% full
c) Use an EPA-approved recovery device and a dedicated
recovery cylinder
d) Recover liquid only, never vapor
Answer: c
Rationale: EPA 608 prohibits venting; recovery must use certified
equipment. Cylinders must never exceed 80% fill to prevent
hydraulic rupture.
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2. A combustible gas detector should be used before:
a) Changing a thermostat
b) Brazing or soldering near gas lines
c) Adding refrigerant to a heat pump
d) Cleaning evaporator coils
Answer: b
Rationale: Brazing near gas piping creates ignition risk. Gas
detectors check for leaks before open flame.
3. A technician is working on a rooftop unit with an electrical
disconnect that tests 0 volts, but the cover is missing. What is
the correct action?
a) Proceed since voltage is 0
b) Replace the cover before starting work
c) Leave the cover off for better access
d) Use a non-contact voltage tester and ignore the cover
Answer: b
Rationale: Missing covers expose live terminals (even if
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disconnected). Re-install or replace cover to meet OSHA/NEC
safety standards.
4. What is the minimum clearance required in front of an
electrical panel serving HVAC equipment (per NEC)?
a) 18 inches
b) 24 inches
c) 30 inches
d) 36 inches
Answer: c (30 inches width or 36 inches depth depending
on voltage; 30” is standard for working space)
Rationale: NEC 110.26 requires 30” width and 36” depth for
equipment over 150V to ground.
5. A technician smells refrigerant indoors. The first step is:
a) Evacuate the building and call the fire department
b) Ventilate the area and locate the leak
c) Add more refrigerant to stop the leak
d) Turn off the HVAC system and ignore
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Answer: b
Rationale: Ventilate to reduce concentration, then find leak per
EPA protocols. Evacuation only if high concentration or health
symptoms.
6. What type of fire extinguisher is rated for electrical fires?
a) Class A
b) Class B
c) Class C
d) Class D
Answer: c
Rationale: Class C for energized electrical equipment;
non-conductive agent.
7. A recovery cylinder should never be heated above:
a) 100°F
b) 122°F
c) 140°F
d) 150°F
HVAC CONTRACTOR EXAM QUESTIONS
AND ANSWERS
1. When recovering refrigerant from a system, the technician
must:
a) Vent refrigerant into the atmosphere if below 5 lbs
b) Use a recovery cylinder that is over 80% full
c) Use an EPA-approved recovery device and a dedicated
recovery cylinder
d) Recover liquid only, never vapor
Answer: c
Rationale: EPA 608 prohibits venting; recovery must use certified
equipment. Cylinders must never exceed 80% fill to prevent
hydraulic rupture.
,Page 2 of 161
2. A combustible gas detector should be used before:
a) Changing a thermostat
b) Brazing or soldering near gas lines
c) Adding refrigerant to a heat pump
d) Cleaning evaporator coils
Answer: b
Rationale: Brazing near gas piping creates ignition risk. Gas
detectors check for leaks before open flame.
3. A technician is working on a rooftop unit with an electrical
disconnect that tests 0 volts, but the cover is missing. What is
the correct action?
a) Proceed since voltage is 0
b) Replace the cover before starting work
c) Leave the cover off for better access
d) Use a non-contact voltage tester and ignore the cover
Answer: b
Rationale: Missing covers expose live terminals (even if
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disconnected). Re-install or replace cover to meet OSHA/NEC
safety standards.
4. What is the minimum clearance required in front of an
electrical panel serving HVAC equipment (per NEC)?
a) 18 inches
b) 24 inches
c) 30 inches
d) 36 inches
Answer: c (30 inches width or 36 inches depth depending
on voltage; 30” is standard for working space)
Rationale: NEC 110.26 requires 30” width and 36” depth for
equipment over 150V to ground.
5. A technician smells refrigerant indoors. The first step is:
a) Evacuate the building and call the fire department
b) Ventilate the area and locate the leak
c) Add more refrigerant to stop the leak
d) Turn off the HVAC system and ignore
, Page 4 of 161
Answer: b
Rationale: Ventilate to reduce concentration, then find leak per
EPA protocols. Evacuation only if high concentration or health
symptoms.
6. What type of fire extinguisher is rated for electrical fires?
a) Class A
b) Class B
c) Class C
d) Class D
Answer: c
Rationale: Class C for energized electrical equipment;
non-conductive agent.
7. A recovery cylinder should never be heated above:
a) 100°F
b) 122°F
c) 140°F
d) 150°F
