2431 HVAC EXAM QUESTIONS WITH
CORRECT ANSWERS 2026
When is the transformer's primary energized (have power applied to it)? - CORRECT ANSWER -
Any time the furnace has power applied.
When a short occurs in a device in the 24 volt control circuit, it will have what effect on the transformer?
- CORRECT ANSWER -Both A & B
Where is the transformer's primary connected in the electric furnace? - CORRECT ANSWER -
It is connected to the terminal block.
What is the function of the contactor? - CORRECT ANSWER -
To make or break the 240 volt circuit to the outdoor fan motor and compressor.
What is the function of the transformer in a residential electric furnace? - CORRECT ANSWER -
To step the voltage down to 24 volts.
How does the transformer achieve its designed function? - CORRECT ANSWER -
By a process called electromagnetic induction.
The contactor's solenoid is connected to the common side of the transformer and the: -
CORRECT ANSWER -yellow terminal of the thermostat.
When is the solenoid of the contqactor energized (have power applied)? - CORRECT ANSWER -
When the thermostat calls for cool.
What is the function of the indoor fan relay? - CORRECT ANSWER -
To select the correct fan speed for the cooling mode.
Where are the normally closed contacts on the indoor fan relay connected? - CORRECT ANSWER -
To the low speed tap on the indoor fan motor.
, If the indoor blower motor does not need a run capacitor then it is: - CORRECT ANSWER -
A shaded pole motor
The solenoid of the indoor fan relay is connected to the common side of the transformer and the: -
CORRECT ANSWER -green terminal of the thermostat.
What is the function of the sequencer? - CORRECT ANSWER -
To stage the heating elements on one at a time.
The second stage of the sequencer completes the circuit to the:
] - CORRECT ANSWER -Low speed tap of the indoor fan motor.
A residentioal electric furnace rated at 15KW will have: - CORRECT ANSWER -Three heating elements.
What protects the heating element of an electric furance? - CORRECT ANSWER -A fuse link
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Thexsequencerxcontainsxax_________xdevice.x-xCORRECTxANSWERx-bimetal
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CORRECT ANSWERS 2026
When is the transformer's primary energized (have power applied to it)? - CORRECT ANSWER -
Any time the furnace has power applied.
When a short occurs in a device in the 24 volt control circuit, it will have what effect on the transformer?
- CORRECT ANSWER -Both A & B
Where is the transformer's primary connected in the electric furnace? - CORRECT ANSWER -
It is connected to the terminal block.
What is the function of the contactor? - CORRECT ANSWER -
To make or break the 240 volt circuit to the outdoor fan motor and compressor.
What is the function of the transformer in a residential electric furnace? - CORRECT ANSWER -
To step the voltage down to 24 volts.
How does the transformer achieve its designed function? - CORRECT ANSWER -
By a process called electromagnetic induction.
The contactor's solenoid is connected to the common side of the transformer and the: -
CORRECT ANSWER -yellow terminal of the thermostat.
When is the solenoid of the contqactor energized (have power applied)? - CORRECT ANSWER -
When the thermostat calls for cool.
What is the function of the indoor fan relay? - CORRECT ANSWER -
To select the correct fan speed for the cooling mode.
Where are the normally closed contacts on the indoor fan relay connected? - CORRECT ANSWER -
To the low speed tap on the indoor fan motor.
, If the indoor blower motor does not need a run capacitor then it is: - CORRECT ANSWER -
A shaded pole motor
The solenoid of the indoor fan relay is connected to the common side of the transformer and the: -
CORRECT ANSWER -green terminal of the thermostat.
What is the function of the sequencer? - CORRECT ANSWER -
To stage the heating elements on one at a time.
The second stage of the sequencer completes the circuit to the:
] - CORRECT ANSWER -Low speed tap of the indoor fan motor.
A residentioal electric furnace rated at 15KW will have: - CORRECT ANSWER -Three heating elements.
What protects the heating element of an electric furance? - CORRECT ANSWER -A fuse link
Whatxisxthexapproximatextemperaturexthatxthexlimitxswitchxonxanxelectricxfurnace'sxheatingxelementxop
en
? -xCORRECTxANSWERx-170xdegrees
Thexsequencerxcontainsxax_________xdevice.x-xCORRECTxANSWERx-bimetal
Thexsequencer'sxheaterxisxconnectedxtoxthexcommonxsidexofxthextransformerxandxthe:
x-
CORRECTxANSWERx-whitexterminalxofxthexthermostat.
Thexlimitxswitchxonxanxelectricxfurnace'sxheatingxelementxsectionxisx_______xclosingxdevice.
x-
CORRECTxANSWERx-Anxautomatically
Whatxisxthexthermostat'sxheatxanticipatorxfunction?x-
xCORRECTxANSWERx-
Preventxthexroom'sxtemperaturexfromxovershootingxthexsetxpoint.
