Carrier 42QHC024DS series - Open or Short Circuit of T1 Temperature Sensor E4; Open or Short Circuit of T2 Temperature Sensor E5; Open or Short Circuit of T3 Temperature Sensor F2 O; Open or Short Circuit of T4 Temperature Sensor F1 O

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18.3.1.4 Open or short circuit of temperature sensor.
Check the connections
between temperature
sensor and PCB. Are the
connections good?
Check the connections
between temperature
sensor and PCB. Are the
connections good?
Correct the connections.
Correct the connections.No
Yes
No
Replace the sensor.
Replace the sensor.
Replace the indoor PCB
Replace the indoor PCB
Measure the resistance value
of the sensor via Appendix 1
Measure the resistance value
of the sensor via Appendix 1
Is it normal?
Is it normal?
Yes
18.3.1.5 Full-water malfunction
If the water-level switch
is inserted well?
If the water-level switch
is inserted well?
No
Insert the water-level switch well
Insert the water-level switch well
If the water-level switch
is broken?
If the water-level switch
is broken?
Yes
Replace the water-level switch
Replace the water-level switch
Replace the water pump, If
malfunction is still not
solved
Replace the water pump, If
malfunction is still not
solved
Yes
No
Yes
Replace the indoor main PCB
Replace the indoor main PCB
Power off, then restart the unit 2 minutes
later. Is it still displaying the error code?
Power off, then restart the unit 2 minutes
later. Is it still displaying the error code?
Yes