Thermistor Or Related Abnormality (Outdoor Unit) - Daikin CTXU25G2V1B Service Manual

SiBE12-908

2.27 Thermistor or Related Abnormality (Outdoor Unit)

P4 , J3 , J6 , J8 , J9 , H9
Remote
Controller Display
Method of This fault is identified based on the thermistor input voltage to the microcomputer.
A thermistor fault is identified based on the temperature detected by each thermistor.
Malfunction
Detection
Malfunction When power is supplied and the thermistor input is 4.98 V or more
or when the thermistor input is 0.02 V or less for 5 seconds continuously
Decision
Conditions
For J3 ,
"Discharge pipe thermistor < heat exchanger thermistor" is taken into consideration to identify
the fault.
For J8 or J9 , although the system of the corresponding room is shut down, the outdoor unit can
operate.
Supposed
Causes
Service Diagnosis
Improper connection of connector
Defective thermistor
Defective indoor unit PCB
For J3 , defective heat exchanger thermistor
(Cooling: outdoor heat exchanger thermistor, heating: indoor heat exchanger thermistor)
Troubleshooting
146