Troubleshooting Sheet
1.3.5 Open circuit or short circuit of temperature sensor diagnosis and solution(E5) 
Error Code 
E4/E5/F1/F2/F3 
Malfunction decision 
conditions 
If the sampling voltage is lower than 0.06V or higher than 4.94V, 
the LED will display the failure. 
Supposed causes 
● 
Wiring mistake 
●  Sensor faulty 
● 
PCB faulty 
Trouble shooting: 
Check the connection 
between temperature 
sensor and PCB.
Correct the connectionNo
Yes
Replace indoor or outdoor 
main PCB
Measure the resistance 
value of the sensor
Repalce the sensorNo
Yes










