Service Diagnosis
35
Domestic air conditioner
Caution
Be sure to turn off power switch before connect or disconnect connector, or else
parts damage may be occurred.
11.4.1 Thermistor or Related Abnormality
Indoor Display E1: Room temperature sensor failure
E2: Heat-exchange 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
Note: 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
