CALIFORNIA HVAC CONTRACTOR PRACTICE EXAM
200 QUESTIONS & CORRECT ANSWERS LATEST
2026/2027
What is the maximum distance a ladder should extend above the roof line or
support point? - ANSWER-3 feet
According to Title 24, what is the maximum allowed leakage for a new duct
system in a residential retrofit? - ANSWER-5%
What describes the 'latent heat of vaporization'? - ANSWER-The heat required to
change a liquid into a gas without a change in temperature.
What is the most likely cause if a technician finds the compressor running but the
indoor blower not operating? - ANSWER-Failed blower motor capacitor or relay.
What is the requirement for combustion air when installing a gas furnace in a
closet? - ANSWER-Two permanent openings, one within 12 inches of the top and
one within 12 inches of the bottom.
What is the effect of an undersized suction line on a cooling system? - ANSWER-
Reduced system efficiency and potential compressor overheating.
Under California law, what must a home improvement contract include? -
ANSWER-A 'Notice to Owner' regarding mechanics' liens.
,In a series circuit with three resistors of 10, 20, and 30 ohms, what is the total
resistance? - ANSWER-60 ohms
What is the primary purpose of a TXV (Thermostatic Expansion Valve)? -
ANSWER-To maintain a constant superheat at the evaporator outlet.
What should a contractor do first if a customer complains of a 'rotten egg' smell
near their floor furnace? - ANSWER-Shut off the gas supply and evacuate the area
if necessary.
What is the minimum gauge for a galvanized steel 6-inch round smoke pipe (flue)?
- ANSWER-26 gauge
Which instrument is used to measure the velocity of air in a duct? - ANSWER-
Anemometer
What is a violation if a contractor abandons a project after receiving 50% of the
payment without finishing the work? - ANSWER-The Business and Professions
Code.
What does a 'SEER' rating measure? - ANSWER-The seasonal energy efficiency
ratio of an air conditioner.
What is the purpose of a crankcase heater on a heat pump? - ANSWER-To prevent
refrigerant migration to the oil during the off-cycle.
Which of the following is considered a hazardous material in older HVAC
installations? - ANSWER-Asbestos-containing duct wrap
, What happens to the boiling point of a refrigerant as the pressure increases? -
ANSWER-The boiling point increases.
What is the maximum height of a Category I furnace vent above the roof line for a
flat roof? - ANSWER-1 foot
What does an 'OL' reading indicate when testing a motor winding with a digital
multimeter set to 'Ohms'? - ANSWER-An open circuit.
What gas is used to purge the lines when brazing copper joints to prevent
oxidation? - ANSWER-Nitrogen
What is the standard CFM required per ton of cooling for a residential application?
- ANSWER-400 CFM
What is the maximum current a 24V transformer rated at 40VA can handle? -
ANSWER-1.67 amps
Which refrigerant has the lowest Global Warming Potential (GWP)? - ANSWER-
R-32
What does a high subcooling reading likely indicate on a system with a TXV? -
ANSWER-An overcharge of refrigerant.
What is the required slope for a horizontal condensate drain line? - ANSWER-1/8
to 1/4 inch per foot
What does 'Static Pressure' represent in HVAC? - ANSWER-The outward pressure
exerted by the air against the duct walls.
200 QUESTIONS & CORRECT ANSWERS LATEST
2026/2027
What is the maximum distance a ladder should extend above the roof line or
support point? - ANSWER-3 feet
According to Title 24, what is the maximum allowed leakage for a new duct
system in a residential retrofit? - ANSWER-5%
What describes the 'latent heat of vaporization'? - ANSWER-The heat required to
change a liquid into a gas without a change in temperature.
What is the most likely cause if a technician finds the compressor running but the
indoor blower not operating? - ANSWER-Failed blower motor capacitor or relay.
What is the requirement for combustion air when installing a gas furnace in a
closet? - ANSWER-Two permanent openings, one within 12 inches of the top and
one within 12 inches of the bottom.
What is the effect of an undersized suction line on a cooling system? - ANSWER-
Reduced system efficiency and potential compressor overheating.
Under California law, what must a home improvement contract include? -
ANSWER-A 'Notice to Owner' regarding mechanics' liens.
,In a series circuit with three resistors of 10, 20, and 30 ohms, what is the total
resistance? - ANSWER-60 ohms
What is the primary purpose of a TXV (Thermostatic Expansion Valve)? -
ANSWER-To maintain a constant superheat at the evaporator outlet.
What should a contractor do first if a customer complains of a 'rotten egg' smell
near their floor furnace? - ANSWER-Shut off the gas supply and evacuate the area
if necessary.
What is the minimum gauge for a galvanized steel 6-inch round smoke pipe (flue)?
- ANSWER-26 gauge
Which instrument is used to measure the velocity of air in a duct? - ANSWER-
Anemometer
What is a violation if a contractor abandons a project after receiving 50% of the
payment without finishing the work? - ANSWER-The Business and Professions
Code.
What does a 'SEER' rating measure? - ANSWER-The seasonal energy efficiency
ratio of an air conditioner.
What is the purpose of a crankcase heater on a heat pump? - ANSWER-To prevent
refrigerant migration to the oil during the off-cycle.
Which of the following is considered a hazardous material in older HVAC
installations? - ANSWER-Asbestos-containing duct wrap
, What happens to the boiling point of a refrigerant as the pressure increases? -
ANSWER-The boiling point increases.
What is the maximum height of a Category I furnace vent above the roof line for a
flat roof? - ANSWER-1 foot
What does an 'OL' reading indicate when testing a motor winding with a digital
multimeter set to 'Ohms'? - ANSWER-An open circuit.
What gas is used to purge the lines when brazing copper joints to prevent
oxidation? - ANSWER-Nitrogen
What is the standard CFM required per ton of cooling for a residential application?
- ANSWER-400 CFM
What is the maximum current a 24V transformer rated at 40VA can handle? -
ANSWER-1.67 amps
Which refrigerant has the lowest Global Warming Potential (GWP)? - ANSWER-
R-32
What does a high subcooling reading likely indicate on a system with a TXV? -
ANSWER-An overcharge of refrigerant.
What is the required slope for a horizontal condensate drain line? - ANSWER-1/8
to 1/4 inch per foot
What does 'Static Pressure' represent in HVAC? - ANSWER-The outward pressure
exerted by the air against the duct walls.
