NCCER HVAC Level 2 Certification Exam Prep Latest
2025–2026 Edition | 150 Actual Exam Questions
Collections with Verified Answers and Detailed
Rationales | Comprehensive Review of Refrigerants and
Oils, Compressors, Metering Devices, Alternating
Current, Leak Detection, Evacuation Recovery and
Charging, Heat Pumps, Indoor Air Quality, Air Quality
Equipment, Chimneys, Vents and Flues, Customer
Relations and Basic Maintenance | Tutor Verified
Success | Grade A+ | Instant Download PDF
1. A technician is troubleshooting a split-system air conditioner with low
cooling capacity. The suction pressure is lower than normal and superheat
is high. What is the most likely cause?
A. Overcharged refrigerant
B. Restricted metering device
C. Dirty condenser coil
D. High indoor airflow
✔ Correct Answer: B. Restricted metering device
Explanation: High superheat and low suction pressure indicate starvation
of refrigerant, commonly caused by a restriction at the metering device.
2. When performing a deep vacuum on a refrigeration system, what level must
be achieved before charging?
A. 5000 microns
B. 2500 microns
C. 500 microns
D. 100 microns
✔ Correct Answer: C. 500 microns
, Explanation: Industry standards require evacuation to at least 500 microns
to remove moisture and non-condensables effectively.
3. A system using a thermostatic expansion valve (TXV) shows normal head
pressure but low suction pressure. What should be checked first?
A. Compressor valves
B. TXV bulb placement
C. Condenser fan speed
D. Refrigerant type
✔ Correct Answer: B. TXV bulb placement
Explanation: Improper bulb placement affects TXV operation, leading to
incorrect refrigerant flow.
4. Which component prevents refrigerant from flowing backward during off
cycles?
A. Accumulator
B. Receiver
C. Check valve
D. Sight glass
✔ Correct Answer: C. Check valve
Explanation: A check valve ensures one-directional refrigerant flow,
preventing backflow.
5. In a heat pump during heating mode, which coil acts as the condenser?
A. Outdoor coil
B. Indoor coil
C. Evaporator coil
D. Expansion coil
✔ Correct Answer: B. Indoor coil
Explanation: In heating mode, the indoor coil releases heat and functions
as the condenser.
6. A technician measures high head pressure and normal suction pressure.
What is a likely cause?
, A. Low refrigerant charge
B. Dirty condenser coil
C. Faulty compressor
D. Restricted evaporator
✔ Correct Answer: B. Dirty condenser coil
Explanation: A dirty condenser reduces heat rejection, increasing head
pressure.
7. What is the primary function of a liquid receiver?
A. Store refrigerant
B. Increase pressure
C. Filter debris
D. Control airflow
✔ Correct Answer: A. Store refrigerant
Explanation: The receiver holds excess liquid refrigerant for system
stability.
8. A system has frost forming on the suction line. What is the most likely
issue?
A. High airflow
B. Low refrigerant
C. Restricted airflow
D. High superheat
✔ Correct Answer: C. Restricted airflow
Explanation: Restricted airflow causes low evaporator temperature,
leading to frosting.
9. Which instrument measures airflow in ducts?
A. Manometer
B. Psychrometer
C. Anemometer
D. Hygrometer
✔ Correct Answer: C. Anemometer
Explanation: An anemometer measures air velocity and airflow.
, 10.What is the function of a crankcase heater?
A. Increase oil pressure
B. Prevent refrigerant migration
C. Cool compressor
D. Improve airflow
✔ Correct Answer: B. Prevent refrigerant migration
Explanation: It keeps refrigerant from condensing in the compressor oil
during off cycles.
11.A technician observes short cycling in a system. What is a common cause?
A. Dirty filter
B. Oversized system
C. Low voltage
D. High humidity
✔ Correct Answer: B. Oversized system
Explanation: Oversized systems cool quickly and shut off frequently,
causing short cycling.
12.What is superheat?
A. Heat removed from condenser
B. Temperature above boiling point
C. Pressure difference
D. Latent heat
✔ Correct Answer: B. Temperature above boiling point
Explanation: Superheat measures how much vapor temperature exceeds
saturation temperature.
13.Which refrigerant is commonly used as a replacement for R-22?
A. R-134a
B. R-410A
C. R-12
D. R-502
✔ Correct Answer: B. R-410A
Explanation: R-410A is widely used in modern systems replacing R-22.
2025–2026 Edition | 150 Actual Exam Questions
Collections with Verified Answers and Detailed
Rationales | Comprehensive Review of Refrigerants and
Oils, Compressors, Metering Devices, Alternating
Current, Leak Detection, Evacuation Recovery and
Charging, Heat Pumps, Indoor Air Quality, Air Quality
Equipment, Chimneys, Vents and Flues, Customer
Relations and Basic Maintenance | Tutor Verified
Success | Grade A+ | Instant Download PDF
1. A technician is troubleshooting a split-system air conditioner with low
cooling capacity. The suction pressure is lower than normal and superheat
is high. What is the most likely cause?
A. Overcharged refrigerant
B. Restricted metering device
C. Dirty condenser coil
D. High indoor airflow
✔ Correct Answer: B. Restricted metering device
Explanation: High superheat and low suction pressure indicate starvation
of refrigerant, commonly caused by a restriction at the metering device.
2. When performing a deep vacuum on a refrigeration system, what level must
be achieved before charging?
A. 5000 microns
B. 2500 microns
C. 500 microns
D. 100 microns
✔ Correct Answer: C. 500 microns
, Explanation: Industry standards require evacuation to at least 500 microns
to remove moisture and non-condensables effectively.
3. A system using a thermostatic expansion valve (TXV) shows normal head
pressure but low suction pressure. What should be checked first?
A. Compressor valves
B. TXV bulb placement
C. Condenser fan speed
D. Refrigerant type
✔ Correct Answer: B. TXV bulb placement
Explanation: Improper bulb placement affects TXV operation, leading to
incorrect refrigerant flow.
4. Which component prevents refrigerant from flowing backward during off
cycles?
A. Accumulator
B. Receiver
C. Check valve
D. Sight glass
✔ Correct Answer: C. Check valve
Explanation: A check valve ensures one-directional refrigerant flow,
preventing backflow.
5. In a heat pump during heating mode, which coil acts as the condenser?
A. Outdoor coil
B. Indoor coil
C. Evaporator coil
D. Expansion coil
✔ Correct Answer: B. Indoor coil
Explanation: In heating mode, the indoor coil releases heat and functions
as the condenser.
6. A technician measures high head pressure and normal suction pressure.
What is a likely cause?
, A. Low refrigerant charge
B. Dirty condenser coil
C. Faulty compressor
D. Restricted evaporator
✔ Correct Answer: B. Dirty condenser coil
Explanation: A dirty condenser reduces heat rejection, increasing head
pressure.
7. What is the primary function of a liquid receiver?
A. Store refrigerant
B. Increase pressure
C. Filter debris
D. Control airflow
✔ Correct Answer: A. Store refrigerant
Explanation: The receiver holds excess liquid refrigerant for system
stability.
8. A system has frost forming on the suction line. What is the most likely
issue?
A. High airflow
B. Low refrigerant
C. Restricted airflow
D. High superheat
✔ Correct Answer: C. Restricted airflow
Explanation: Restricted airflow causes low evaporator temperature,
leading to frosting.
9. Which instrument measures airflow in ducts?
A. Manometer
B. Psychrometer
C. Anemometer
D. Hygrometer
✔ Correct Answer: C. Anemometer
Explanation: An anemometer measures air velocity and airflow.
, 10.What is the function of a crankcase heater?
A. Increase oil pressure
B. Prevent refrigerant migration
C. Cool compressor
D. Improve airflow
✔ Correct Answer: B. Prevent refrigerant migration
Explanation: It keeps refrigerant from condensing in the compressor oil
during off cycles.
11.A technician observes short cycling in a system. What is a common cause?
A. Dirty filter
B. Oversized system
C. Low voltage
D. High humidity
✔ Correct Answer: B. Oversized system
Explanation: Oversized systems cool quickly and shut off frequently,
causing short cycling.
12.What is superheat?
A. Heat removed from condenser
B. Temperature above boiling point
C. Pressure difference
D. Latent heat
✔ Correct Answer: B. Temperature above boiling point
Explanation: Superheat measures how much vapor temperature exceeds
saturation temperature.
13.Which refrigerant is commonly used as a replacement for R-22?
A. R-134a
B. R-410A
C. R-12
D. R-502
✔ Correct Answer: B. R-410A
Explanation: R-410A is widely used in modern systems replacing R-22.
