Domestic Air Conditioner
7.3.5    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:  
Suck  temperature sensor failure  
Indoor display: F7
outdoor display:           LED1 flash 11times: 
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 
Faulty connector connection 
Causes 
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 
HSU12/18VHJ(DB)
        Functions and control
61