Thermistor Or Related Abnormality (Outdoor Unit) - Daikin FTXN25KEV1B Service Manual

SiBE041102_A

4.18 Thermistor or Related Abnormality (Outdoor Unit)

H9 , J3 , J6 , P4
Remote
Controller
Display
Method of This fault is identified based on the thermistor input voltage to the microcomputer.
Malfunction A thermistor fault is identified based on the temperature sensed by each thermistor.
Detection
Malfunction
Decision
Conditions
Supposed
Causes
In case of " P4 "
Troubleshooting
Replace the outdoor unit PCB.
P4
Service Diagnosis
The thermistor input voltage is above 4.96 V or below 0.04 V with the power on.
J3
error is judged if the discharge pipe temperature is lower than the heat exchanger
temperature.
Disconnection of the connector for the thermistor
Defective thermistor corresponding to the error code
Defective heat exchanger thermistor in the case of J3 error (outdoor heat exchanger
thermistor in cooling operation, or indoor heat exchanger thermistor in heating operation)
Defective outdoor unit PCB
Be sure to turn off the power switch before connecting or disconnecting
Caution connectors, or parts may be damaged.
: Radiation fin thermistor
Troubleshooting
75