Service diagnosis
33
Domestic air conditioner
10.3.1 Thermistor or Related Abnormality
Indoor Display
★
Room temperature sensor failure
Heat-exchange sensor failure
Outdoor display
flash 10 times
Defrost temperature sensor failure
flash 11 times
Suction temperature sensor failure
flash 12 times
Ambient temperature sensor failure
flash 13 times
Discharge temperature sensor failure
Method of
The temperatures detected by the thermistors are used to determine thermistor errors
Malfunction
Detection
Malfunction When the thermistor input is more than 4.92V or less than 0.08V during compressor
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Conditions
The values vary slightly in some models
Supposed
Faulty connector connection
Causes
Faulty thermistor
Faulty PCB
Troubleshooting * Caution
Be sure to turn off power switch before connect or disconnect connector, or
else parts damage may be occurred.
Thermistor resistance check method
Remove the connector of the thermistor on the PCB, and measure the resistance of thermistor using tester.The
relationship between normal temperature and resistance is shown in the value of indoor thermistor.
Thermistor resistance check
Is it normal?
Yes
NO
Yes
Is it normal?
NO
Check the connector connection.
Replace the thermistor
Replace the indoor unit PCB
Correct the connection