Haier HSU-09RS03/R2(SDB) Service Manual page 57

7.4.1Thermistor or Related Abnormality (indoor unit)
E1: Room temperature sensor failure
Indoor Display
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
Decision operation.
Conditions
* Note: The values vary slightly in some models
Supposed
Causes
Troubleshooting * Caution Be sure to turn off power switch before connect or disconnect connector, or
Check the connector
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-09/12RS03/R2(SDB)
E2: Heat-exchange sensor failure
Faulty connector connection
Faulty thermistor
Faulty PCB
else parts damage may be occurred.
ti
Is it normal?
Yes
Is it normal?
NO
Correct the connection
NO
Replace the thermistor
Yes
Replace the indoor unit PCB
54
Service Diagnosis
Domestic air conditioner