7.2.5 Thermistor or Related Abnormality(outdoor unit)
Frost-removing temperature sensor failure
Indoor display:
F21
outdoor display: LED1 flash 10 times:
Exhaust temperature sensor failure
Indoor display:
F25
outdoor display: LED1 flash 13 times:
Ambient temperature sensor failure
Indoor display:
F6
outdoor display: LED1 flash 12 times:
Method of
This type of error is detected by checking the thermistor input voltage to the microcomputer.
Malfunction
(A thermistor error is detected by checking the temperature)
Detection
Malfunction
The thermistor input is above 4.9V or below 0.1V with the power on.
Decision
Conditions * Note:
The values may 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.
NO
YES
NO
YES
Is it normal?
Check the connector connection.
Thermistor resistance check
Correct the connection
Is it normal?
Replace the thermistor
Replace the outdoor unit PCB
HSU-18,22HVA103/R2(DB) Service Diagnosis
81
Domestic Air Conditioner