NATE HEAT PUMP EXAM QUESTIONS
WITH CORRECT ANSWER 2026/2027
GRADED A+/ GUARANTEED PASS
1. A control string is defined as two or more switch contacts connected in
a circuit or set of circuits, to control a load. In order to troubleshoot a
load controlled by a control string, the technician must first: - ANS
✅✅-a. check for proper voltage applied across the load
2. A disc type, close-on rise pressure control is being used as a loss-of-
charge limit control on the liquid line of a heat pump. The control must
sense a specified pressure within 15 seconds of a compressor start for
the compressor to continue operation. If the cut-in setting of the
control drifts lower, what will this mean to the performance of the
system? - ANS ✅✅-c. the system is less likely to shut down as a result
of a small leak
3. A heat pump operates normally in first stage heating. The first and
second stage bulb appear to be calling, the compressor continues to
run, but the auxiliary electric heat does not come on. Which of the
following should be included as a likely source of the problem? - ANS
✅✅-a. the second stage heating circuit is open
4. A high pressure limit control, used to shut down a compressor if
condensing pressure becomes excessive, is typically installed to sense
- ANS ✅✅-c. compressor discharge line pressure
5. A line voltage fuse is sized to: - ANS ✅✅-a. protect the conductors
, 6. A reason for cool air complaints when a heat pump is operating in the
heating cycle is: - ANS ✅✅-C. excessive supply air velocities b. dirty
return air filters
7. A residential supply diffuser that is noisy because of a loose van is best
serviced by: - ANS ✅✅-d. replacing the diffuser
8. A suction line accumulator should be used in a residential heat pump
only when recommended by the
9. manufacturer if - ANS ✅✅-a. long refrigerant lines increase system
charge over recommended maximum charge
10. A system is supplied from the factory with charge for a 15 foot
line set. The dataplate shows the required system charge to be 5
pounds 10 ounces. The line set uses a 3/8 inch liquid line and is 25 feet
long. The manufacturer's instruction sheet specifies 0.6 ounces of
refrigerant to be added for each added foot of refrigerant line length.
What is the total refrigerant charge for the system? - ANS ✅✅-d. 6
pounds
11. A technician has determined a supply in a flexible duct system is
leaking. Which of the following should be checked? - ANS ✅✅-d. all
connections including inner and outer duct only layers
12. A technician has the following conditions while checking a
packaged heat pump in cooling. - ANS ✅✅-a. the unit is low on charge
refrigerant needs to be added
13. A technician is working on a heat pump with a capacitor start
capacitor run compressor. On initial
14. startup, the compressor hums momentarily and then shuts down
on internal overload. Which of the following is the most likely problem?
- ANS ✅✅-c. potential relay is not functioning
WITH CORRECT ANSWER 2026/2027
GRADED A+/ GUARANTEED PASS
1. A control string is defined as two or more switch contacts connected in
a circuit or set of circuits, to control a load. In order to troubleshoot a
load controlled by a control string, the technician must first: - ANS
✅✅-a. check for proper voltage applied across the load
2. A disc type, close-on rise pressure control is being used as a loss-of-
charge limit control on the liquid line of a heat pump. The control must
sense a specified pressure within 15 seconds of a compressor start for
the compressor to continue operation. If the cut-in setting of the
control drifts lower, what will this mean to the performance of the
system? - ANS ✅✅-c. the system is less likely to shut down as a result
of a small leak
3. A heat pump operates normally in first stage heating. The first and
second stage bulb appear to be calling, the compressor continues to
run, but the auxiliary electric heat does not come on. Which of the
following should be included as a likely source of the problem? - ANS
✅✅-a. the second stage heating circuit is open
4. A high pressure limit control, used to shut down a compressor if
condensing pressure becomes excessive, is typically installed to sense
- ANS ✅✅-c. compressor discharge line pressure
5. A line voltage fuse is sized to: - ANS ✅✅-a. protect the conductors
, 6. A reason for cool air complaints when a heat pump is operating in the
heating cycle is: - ANS ✅✅-C. excessive supply air velocities b. dirty
return air filters
7. A residential supply diffuser that is noisy because of a loose van is best
serviced by: - ANS ✅✅-d. replacing the diffuser
8. A suction line accumulator should be used in a residential heat pump
only when recommended by the
9. manufacturer if - ANS ✅✅-a. long refrigerant lines increase system
charge over recommended maximum charge
10. A system is supplied from the factory with charge for a 15 foot
line set. The dataplate shows the required system charge to be 5
pounds 10 ounces. The line set uses a 3/8 inch liquid line and is 25 feet
long. The manufacturer's instruction sheet specifies 0.6 ounces of
refrigerant to be added for each added foot of refrigerant line length.
What is the total refrigerant charge for the system? - ANS ✅✅-d. 6
pounds
11. A technician has determined a supply in a flexible duct system is
leaking. Which of the following should be checked? - ANS ✅✅-d. all
connections including inner and outer duct only layers
12. A technician has the following conditions while checking a
packaged heat pump in cooling. - ANS ✅✅-a. the unit is low on charge
refrigerant needs to be added
13. A technician is working on a heat pump with a capacitor start
capacitor run compressor. On initial
14. startup, the compressor hums momentarily and then shuts down
on internal overload. Which of the following is the most likely problem?
- ANS ✅✅-c. potential relay is not functioning
