Service Diagnosis
47
Domestic Air Conditioner
7.4.1
 Thermistor or Related Abnormality 
Indoor Display          E1: Room temperature sensor failure 
E2: Heat-exchange sensor failure       
 outdoor display     LED1  flash 10 times
Defrost temperature sensor failure 
LED1  flash 11 times
Suction temperature sensor failure 
LED1  flash 12 times
Ambient temperature sensor failure 
LED1  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   
  .noitarepo         noisiceD
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 onnection.
Replace the thermistor 
Replace the indoor unit PCB 
Correct the connection