M5LCY-II_(i)
Troubleshooting
49
Error Codes
Error Description
Action
A6
Indoor fan motor abnormal
1. Check the indoor fan by rotating with hand.
2. Replace indoor fan motor if not rotating smoothly.
3. Check fan motor voltage.
4. Replace indoor PCB if not at the rated voltage.
5. Check fan capacitor’s conductivity (AC Motor).
6. Replace fan capacitor if there’s conductivity.
C4
Indoor heat exchanger thermistor
short/open
1. Check the connector connection.
2. Check the sensor resistance value.
C9
Indoor room thermistor short/open
E1
Outdoor PCB error
1. Restart the system.
2. Replace outdoor PCB.
3. Check to see that the unit is grounded.
4. Check power supply waveform.
E3
High pressure protection
1. Check installation conditions.
2. Check stop valve.
3. Check HPS connection.
4. Check pressure level by pressure gauge.
5. Wait for 10 minutes then restart the system.
6. Check if H3 is displayed.
E4
Low pressure protection
1. Check stop valve.
2. Check low pressure sensor connection.
3. Check low side pressure and voltage.
4. Check outdoor coil sensor connection.
5. Check sensor resistance value.
6. Check refrigerant level.
E5
Compressor motor lock/overload
1. Check connection on discharge pipe sensor.
2. Check discharge pipe sensor resistance value.
3. Check the EXV.
4. Check the refrigerant line on blockage or
shortage.
E6
Compressor lock/start-up error
1. Check with inverter checker.
2. Check the EXV.
E7
Outdoor DC fan motor lock
1. Check the fan motor connection.
2. Check if foreign matters exist around or in the fan.
E8
Ac input over current
1. Measure the input current.
2. Check the main circuit electrolytic capacitor.
3. Check with inverter checker.
4. Check discharge pressure.
5. Check the installation condition.