Mitsubishi Heavy Aircon Error Codes

Search any Mitsubishi Heavy Industries error code below. Each entry shows what the code means, how urgent it is, and what to do next — with notes specific to Singapore installations.

Error Code Lookup

Type a code or filter by fault type. Expand any row for full details. For LED blink patterns, see the Mitsubishi Heavy diagnostic guide.

Filter by fault type

Ready to Get Started?

Tell us what’s going on. Symptoms, setup, photos, anything we should know. We’ll assess and come back with the right next step.

Describe your situation

Mitsubishi Heavy Aircon Error Codes

Error Code Lookup

E1Indoor unit PCB / communication fault between indoor PCB and other components

E3Outdoor unit fan motor fault - motor overload or locked rotor detected

E5Indoor unit fan motor fault - indoor fan motor overload or failure

E6Communication error between indoor and outdoor units

E7Outdoor ambient temperature sensor fault - sensor open circuit or short circuit

E9Indoor room temperature sensor fault - thermistor open circuit or short circuit detected

E16Indoor heat exchanger (evaporator coil) temperature sensor fault

E19Outdoor heat exchanger (condenser coil) temperature sensor fault

E36High-pressure protection - refrigerant circuit high pressure exceeded safety limit

E40Low-pressure protection - refrigerant circuit pressure dropped below safe operating level

E49Compressor overload / overcurrent protection - compressor drawing excessive current

E53Outdoor unit PCB fault - outdoor control board malfunction or failure

E59Inverter compressor drive fault - inverter module / IPM failure

E73Outdoor discharge pipe temperature sensor fault - high discharge temperature protection triggered

E74Over-voltage / under-voltage protection - supply voltage out of acceptable range

E80Drain pump fault or condensate drainage system error

U4Refrigerant system abnormality / refrigerant shortage detected by system monitoring

U5Communication error in multi-split system between outdoor unit and multiple indoor units

U8Address setting error - duplicate indoor unit address or incorrect system configuration

FLFilter cleaning reminder - indoor unit air filter requires cleaning

EPElectrical protection fault - general electrical protection circuit activated

EcRefrigerant circuit malfunction - abnormal refrigerant cycle operation detected by system diagnostics

EdExpansion valve fault - electronic expansion valve (EEV) malfunction

EEEEPROM / memory fault - indoor unit control board memory chip error

EHFan motor lock detection - indoor fan motor shaft locked or stalled

SCSelf-cleaning mode activated - unit running self-cleaning cycle to dry evaporator coil