Haier HSU-18,22HVA103/R2(DB) Service Manual page 78

7.2.1Thermistor or Related Abnormality (indoor unit)
Indoor Display
the temperatures detected by the thermistors are used to determine thermistor errors
Method of
Malfunction
Detection
when the thermistor input is more than 4.92V or less than 0.08V during compressor
Malfunction
operation.
Decision
Conditions
* Note: The values vary slightly in some models
■ Faulty connector connection
Supposed
■ Faulty thermistor
Causes
■
* Caution Be sure to turn off power switch before connect or disconnect connector,
Troubleshooting
Check the connector connection.
Thermistor resistance check
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.
HSU-18,22HVA103/R2(DB)
E1: Room temperature sensor failure
E2: Heat-exchange sensor failure
Faulty PCB
else parts damage may be occurred.
Is it normal?
Yes
Is it normal?
NO
Correct the connection
NO
Replace the thermistor
Yes
Replace the indoor unit PCB
77
Service Diagnosis
or
Domestic Air Conditioner