NATE AIR CONDITIONING AND HEAT PUMP EXAM SCRIPT
2025/2026 QUESTIONS WITH ANSWERS GRADED A+
✔✔A bright red or orange glow from the resistance element in a duct heater indicates
that - ✔✔the flow of air is insufficient
✔✔The outdoor fan on a heat pump stops during defrost to - ✔✔minimize defrost time
✔✔A capacitor start-capacitor run (CSCR) motor has an open run capacitor so it may
start, but it draws a _______ than normal running current - ✔✔Higher
✔✔Bent vanes on a direct drive blower wheel in an air handler can cause - ✔✔loss in
airflow, excessive motor wear, and increased noise
✔✔A split system heat pump is using thermostatic expansion valves. The system
performs properly in heating but in cooling the compressor pumps down which could
mean - ✔✔the power element of the indoor expansion valve has lost its charge
✔✔A condition that can cause a reduction from design capacity in a heat pump is -
✔✔an undersized vapor line
✔✔Flash gas in the liquid line of any heat pump must be avoided. Liquid line flash gas
can be caused by - ✔✔excessive liquid line length or lift
✔✔A symptom that a technician would expect on a heat pump system in the cooling
mode if the check valve is leaking internally is a - ✔✔flooding of the indoor coil
✔✔A voltage reading across a closed contact in a 24V control circuit - ✔✔indicates
pitted or dirty contacts
✔✔The first two checks typically made on an electronic control are - ✔✔presence of
proper input signals and proper output voltages
✔✔In a low voltage circuit, a corroded wire-to-terminal connection acts in the circuit like
an - ✔✔additional resistor
✔✔The continuity of a fuse should be tested by checking resistance with - ✔✔power off
✔✔The first check made for most electrical troubleshooting is a - ✔✔voltage check of
the supply line
✔✔To properly check an energized compressor circuit the technician should use a -
✔✔VOM set for volts
, ✔✔The following conditions exist in a circuit that supplies power to three parallel loads.
- ✔✔One load is resistive
One load is capacitive
One load is inductive
The total current in the circuit when operating will be the sum of the currents through
each load
✔✔The technician is using an analog multimeter to check a run capacitor. With the
meter set to ohms the needle swings toward zero and then slowly rises toward infinity,
this tells the technician that the capacitor - ✔✔charges and discharges
✔✔If the technician believes that a hermetic compressor has a permanently open
internal overload protector, the technician should - ✔✔test the compressor while it is
cool
✔✔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 check - ✔✔for proper voltage applied across the load
✔✔When changing out an evaporator coil the installer must be certain to - ✔✔plumb the
cabinet so its sides are vertical
✔✔The recommended maximum external static pressure used for heating and cooling
equipment with blowers for 5 ton of cooling or less is - ✔✔0.1 in W.C
✔✔When a balancing check of a newly installed duct system the dampers should be -
✔✔open completely in all rooms
✔✔Operating sound is a consideration in the location of a condensing unit because -
✔✔excessive noise could be disruptive to the customer
✔✔A technician has determined a supply in a flexible duct system is leaking so - ✔✔All
connections including inner and outer layers should be checked
✔✔Sensible heat ratio is - ✔✔sensible removed ÷ total heat removed
✔✔A wet bulb reading that is very close to the dry bulb reading from the same
instrument indicates the - ✔✔relative humidity is very high
✔✔The following measurements would be needed to properly evaluate a complaint of
"drafty" operation with a heating system are: - ✔✔system TD, drop, and static pressure
2025/2026 QUESTIONS WITH ANSWERS GRADED A+
✔✔A bright red or orange glow from the resistance element in a duct heater indicates
that - ✔✔the flow of air is insufficient
✔✔The outdoor fan on a heat pump stops during defrost to - ✔✔minimize defrost time
✔✔A capacitor start-capacitor run (CSCR) motor has an open run capacitor so it may
start, but it draws a _______ than normal running current - ✔✔Higher
✔✔Bent vanes on a direct drive blower wheel in an air handler can cause - ✔✔loss in
airflow, excessive motor wear, and increased noise
✔✔A split system heat pump is using thermostatic expansion valves. The system
performs properly in heating but in cooling the compressor pumps down which could
mean - ✔✔the power element of the indoor expansion valve has lost its charge
✔✔A condition that can cause a reduction from design capacity in a heat pump is -
✔✔an undersized vapor line
✔✔Flash gas in the liquid line of any heat pump must be avoided. Liquid line flash gas
can be caused by - ✔✔excessive liquid line length or lift
✔✔A symptom that a technician would expect on a heat pump system in the cooling
mode if the check valve is leaking internally is a - ✔✔flooding of the indoor coil
✔✔A voltage reading across a closed contact in a 24V control circuit - ✔✔indicates
pitted or dirty contacts
✔✔The first two checks typically made on an electronic control are - ✔✔presence of
proper input signals and proper output voltages
✔✔In a low voltage circuit, a corroded wire-to-terminal connection acts in the circuit like
an - ✔✔additional resistor
✔✔The continuity of a fuse should be tested by checking resistance with - ✔✔power off
✔✔The first check made for most electrical troubleshooting is a - ✔✔voltage check of
the supply line
✔✔To properly check an energized compressor circuit the technician should use a -
✔✔VOM set for volts
, ✔✔The following conditions exist in a circuit that supplies power to three parallel loads.
- ✔✔One load is resistive
One load is capacitive
One load is inductive
The total current in the circuit when operating will be the sum of the currents through
each load
✔✔The technician is using an analog multimeter to check a run capacitor. With the
meter set to ohms the needle swings toward zero and then slowly rises toward infinity,
this tells the technician that the capacitor - ✔✔charges and discharges
✔✔If the technician believes that a hermetic compressor has a permanently open
internal overload protector, the technician should - ✔✔test the compressor while it is
cool
✔✔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 check - ✔✔for proper voltage applied across the load
✔✔When changing out an evaporator coil the installer must be certain to - ✔✔plumb the
cabinet so its sides are vertical
✔✔The recommended maximum external static pressure used for heating and cooling
equipment with blowers for 5 ton of cooling or less is - ✔✔0.1 in W.C
✔✔When a balancing check of a newly installed duct system the dampers should be -
✔✔open completely in all rooms
✔✔Operating sound is a consideration in the location of a condensing unit because -
✔✔excessive noise could be disruptive to the customer
✔✔A technician has determined a supply in a flexible duct system is leaking so - ✔✔All
connections including inner and outer layers should be checked
✔✔Sensible heat ratio is - ✔✔sensible removed ÷ total heat removed
✔✔A wet bulb reading that is very close to the dry bulb reading from the same
instrument indicates the - ✔✔relative humidity is very high
✔✔The following measurements would be needed to properly evaluate a complaint of
"drafty" operation with a heating system are: - ✔✔system TD, drop, and static pressure
