HVAC NATE HEAT PUMP EXAMS WITH
CORRECT ANSWERS 2026
100,000 BTUH output furnace.
air temp is 65F.
Supply air is 135F.
What is the CFM? - ANSWER-1323CFM
1. A 24v transformer with a 40 VA rating can safely operate with
a current of ________. - ANSWER-1.67 Amps
2. A good fuse will yield a reading of ________on an ohmmeter. -
ANSWER-0 Ω
3. A heat pump operating in normal ice free conditions maintains
a certain temperature difference between the outdoor coil
temperature and the surrounding outdoor ambient. What is
this temperature referred to as? - ANSWER-Coil TD.
4. A high pressure limit control is used for what? - ANSWER-To
shut down a compressor if condensing pressure becomes
excessive
5. A resistance reading of 0 Ω across a coil indicates that the coil
is _____. - ANSWER-shorted
6. A resistance reading of infinity across the "R" terminal and "S"
terminal of a compressor motor indicates a(n) _________. -
ANSWER-open motor winding
,7. A restricted drier can cause what? - ANSWER-Lower than
normal suction pressure
8. A small voltage reading across a closed set of contacts in an
energized circuit indicates that the _______. - ANSWER-contacts
are pitted.
9. A split system heat pump is using thermostatic expansion
valves. The system performs properly in heating but in cooling
the compressor pumps down. What could this mean? -
ANSWER-The power element of the indoor expansion valve has
lost its charge.
10. A step down transformer has a rating of 40 VA. Its
primary voltage is 120V with a secondary voltage of 24V. What
is the maximum current draw of a load connected to this
transformer? - ANSWER-1.7amps
11. A system is supplied from the factory with charge for a 15
foot line set. The data plate 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. How much refrigerant is needed
to completely charge the system? - ANSWER-6lbs
12. A system should operate at least _____ before heat
measurements are taken - ANSWER-20 minutes
13. A technician has determined a supply in a flexible duct
system is leaking. What should be checked? - ANSWER-All
connections inner and outer layers.
, 14. A technician is working on a heat pump with a capacitor
start-capacitor run compressor. On initial startup, the
compressor hums momentarily and the shuts down on internal
overload. What is the problem? - ANSWER-Too great a pressure
difference on the compressor.
15. According to fire protection codes, fire dampers should be
used when? - ANSWER-In any air duct the passes through walls
or partitions of a light commercial installation.
16. According to Ohm's Law, what will happen if voltage to a
heater element is increased 10%? - ANSWER-The current draw
will increase by 10%
17. An acceptable capacitance reading for a run capacitor is
_____ the microfarad
18. rating printed on the capacitor. - ANSWER-plus or minus
10% of.
19. Any individual load on a 24 V control circuit should draw a
measurable current of ______ A. - ANSWER-less than 1Amp
20. Black and white leads on a step-down transformer
indicate a _____. - ANSWER-120-V ac primary
21. Note:
22. Typical color coding:
23. 120 V: black and white primary, yellow and blue
secondary
24. 230 V: red and black primary, yellow and blue secondary
CORRECT ANSWERS 2026
100,000 BTUH output furnace.
air temp is 65F.
Supply air is 135F.
What is the CFM? - ANSWER-1323CFM
1. A 24v transformer with a 40 VA rating can safely operate with
a current of ________. - ANSWER-1.67 Amps
2. A good fuse will yield a reading of ________on an ohmmeter. -
ANSWER-0 Ω
3. A heat pump operating in normal ice free conditions maintains
a certain temperature difference between the outdoor coil
temperature and the surrounding outdoor ambient. What is
this temperature referred to as? - ANSWER-Coil TD.
4. A high pressure limit control is used for what? - ANSWER-To
shut down a compressor if condensing pressure becomes
excessive
5. A resistance reading of 0 Ω across a coil indicates that the coil
is _____. - ANSWER-shorted
6. A resistance reading of infinity across the "R" terminal and "S"
terminal of a compressor motor indicates a(n) _________. -
ANSWER-open motor winding
,7. A restricted drier can cause what? - ANSWER-Lower than
normal suction pressure
8. A small voltage reading across a closed set of contacts in an
energized circuit indicates that the _______. - ANSWER-contacts
are pitted.
9. A split system heat pump is using thermostatic expansion
valves. The system performs properly in heating but in cooling
the compressor pumps down. What could this mean? -
ANSWER-The power element of the indoor expansion valve has
lost its charge.
10. A step down transformer has a rating of 40 VA. Its
primary voltage is 120V with a secondary voltage of 24V. What
is the maximum current draw of a load connected to this
transformer? - ANSWER-1.7amps
11. A system is supplied from the factory with charge for a 15
foot line set. The data plate 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. How much refrigerant is needed
to completely charge the system? - ANSWER-6lbs
12. A system should operate at least _____ before heat
measurements are taken - ANSWER-20 minutes
13. A technician has determined a supply in a flexible duct
system is leaking. What should be checked? - ANSWER-All
connections inner and outer layers.
, 14. A technician is working on a heat pump with a capacitor
start-capacitor run compressor. On initial startup, the
compressor hums momentarily and the shuts down on internal
overload. What is the problem? - ANSWER-Too great a pressure
difference on the compressor.
15. According to fire protection codes, fire dampers should be
used when? - ANSWER-In any air duct the passes through walls
or partitions of a light commercial installation.
16. According to Ohm's Law, what will happen if voltage to a
heater element is increased 10%? - ANSWER-The current draw
will increase by 10%
17. An acceptable capacitance reading for a run capacitor is
_____ the microfarad
18. rating printed on the capacitor. - ANSWER-plus or minus
10% of.
19. Any individual load on a 24 V control circuit should draw a
measurable current of ______ A. - ANSWER-less than 1Amp
20. Black and white leads on a step-down transformer
indicate a _____. - ANSWER-120-V ac primary
21. Note:
22. Typical color coding:
23. 120 V: black and white primary, yellow and blue
secondary
24. 230 V: red and black primary, yellow and blue secondary
