Mitsubishi Heavy Industries AC Error Codes (Simple Solutions)

Mitsubishi commonly referred to as Mitsubishi is a leading multinational electrical equipment and electronics manufacturer. Established in 1921, Mitsubishi still has headquarters in Tokyo. What started as a commercial elevator, escalator, and high-end appliance venture is now offering a wide range of appliances that are available all around the world. Today, the company has come a long way, but its main focus remains on air conditioners, escalators, and other high-end appliances.

Speaking of air conditioning alone, Mitsubishi offers a wide range of systems such as room air conditioners, VRF systems, air curtains, package air conditioners, ventilators, and others. Offering customers a chance to choose anything from a standard air conditioner to a heavy industry AC.

Error codes are a common issue you may face with various appliances in your house or workplace. Rather than panicking, we suggest you grab a pen and paper and note down the code rather than pressing various buttons. This can commonly result in prolonging the issue or even causing more issues in the long run. So why risk damaging your appliance any further, when you will be able to find out the exact issue using the common error code list for Mitsubishi heavy industries AC error codes listed below. Once you know the exact issue you can easily call in a professional, or fix the issue yourself.

Split Systems

Whether a failure exists or not on the indoor unit and outdoor unit can be know by the contents of remote controller error code, indoor/outdoor unit green LED (power pilot lamp and microcomputer normality pilot lamp) or red LED (check pilot lamp).

a.Check Indicator Table

Indoor Unit Side

Error CodesCause
E1When multiple remote controllers are used for control, the power supply to some indoor units is OFF.
Indoor unit PCB fault
The remote controller wire Y is open. The remote controller wires X and Y are reversely connected. Noise is penetrating the remote control lines. The remote controller or indoor control PCB is faulty.
E5Indoor / outdoor transmission error.
Outdoor unit control PCB is faulty when the power is turned on, or the inverter parts are faulty.
Outdoor unit microcomputer failure.
E6Indoor unit heat exchanger thermistor failure
E7Indoor unit return air thermistor failure
E8Heating overload (indoor heat exchanger temperature is abnormally high) and indoor heat exchanger thermistor is faulty.
E9The float SW operates (with FS only). Drain up kit wiring fault.
E10When multi-unit control by remote controller is performed, the number of units is over (more than 17 units). Two remote controller are provided for one controller is performed.
E16Fan motor is faulty (FDTA 501, 601 type, FDKN type)
E28Remote controller thermistor failure

Outdoor Unit Side

Error CodesCause
E32Wiring is open or reversal phase (FDCA 301~601 type)
E33Inverter primary side current is abnormal. (FDCVA151~251 type)
Abnormal current cut of compressor (FDCA 301~601 type)
E3452C secondary side L3-phase wiring is open. (FDCA 301~601 type)
E35Outdoor heat exchanger temperature is high or outdoor heat exchanger thermistor is faulty
E36Discharge temperature abnormality.
E37Outdoor unit heat exchanger thermistor failure
E38Outdoor air temperature thermistor failure
E39Discharge pipe thermistor failure
E4063H1 operation (FDCA 301~601 type)
E42Current (Abnormalities in a compressor over current)
E47Inverter Over-voltage Trouble. (FDCVA 151~251 type)
E48DC fan motor abnormal. (FDCVA 151~251 type)
E5252C abnormal. (FDCA 301~601 type)
E56Power transistor thermistor is faulty or disconnection or connector connections are poor.
E57Insufficient refrigerant.
E59Compressor startup error (FDCVA 151~251 type)
E60Compressor loader position detection error. (FDCVA 151~251 type)
Mitsubishi Heavy Industries Wireless Remote Control
Mitsubishi Heavy Industries Wireless Remote Control

b.Display Sequence of Error, Inspection Display Lamp

Error CodesError Detail
E1Transmission error of remote controller indoor unit. Timing of error detection: After 1 or more communications of the indoor unit with the remote controller following power on, transmission errors cause an interruption for 2 minutes.
E5Transmission error between indoor/outdoor units. Timing of error detection: After communications with the outdoor unit 1 or more times, communications are abnormal continuously for 2 minutes.
E6Broken wire of heat exchanger thermistor. Timing of error detection: When an input temperature of –50°C or lower is measured by the heat exchanger thermistor is measured for 5 seconds or longer within 60 minutes after the first detection.
E7Broken wire of indoor unit return air thermistor. Timing of error detection: When an input temperature of –50°C or lower is measured by the return air thermistor is measured for 5 seconds or longer within 60 minutes after the first detection.
E9Drain error (float switch motion). Timing of error detection: Normally, 30 seconds after the power is turned ON
E10The number of connected indoor units exceeds the connection limit. Timing of error detection: Normally after the power is turned ON (during communications).
E38Broken wire of outdoor air temperature thermistor. Timing of error detection: When a thermistor input temperature of –30°C or lower is measured for 5 seconds or longer 3 times within 40 (60) minutes after the 1st detection between 2 minutes and 2 minutes 20 seconds after compressor operation starts.
E37Broken wire of heat exchanger thermister. Timing of error detection: When a thermistor input temperature of –30°C or lower is measured for 5 seconds or longer 3 times within 40 (60) minutes after the 1st detection between 2 minutes and 2 minutes 20 seconds after compressor operation starts.
E39Broken wire of discharge pipe thermistor. Timing of error detection: When a thermistor input temperature of –10°C or lower is measured for 5 seconds or longer 3 times within 40 (60) minutes after the 1st detection between 10 minutes and 10 minutes 20 seconds (between 2 minutes and 2 minutes 20 seconds) after compressor operation starts.
E55Broken wire of power transistor thermistor. Timing of error detection: When the under-dome thermistor input temperature of –10°C is measured for 5 seconds or longer 3 times within 40 minutes after the 1st detection between 10 minutes and 10 minutes 20 seconds after compressor operation starts.
Mitsubishi Heavy Industries Indication section
Mitsubishi Heavy Industries Indication Section

c.Inverter Wall Mounted Type Room AC Error Codes

Error code, stop code table (Assignment of error codes and stop codes is done in common for all models.)

Error CodesCause
11Compressor lock. Compressor wiring short circuit. Compressor output is open phase. Outdoor unit’s circuit board is faulty.
12Service valve closed. Compressor output is open phase. Electronic expansion valve is faulty.
13Service valve is closed. Compressor output is open phase. Compressor is faulty. Electronic expansion valve is faulty.
14Outdoor unit’s circuit board is defective. Power supply is abnormal.
15Outdoor unit’s circuit board is faulty. Power transistor is damaged.
16Outdoor unit’s circuit board is faulty. Power transistor is damaged.
21Compressor wiring is disconnected. Power transistor is damaged.
22Compressor wiring is disconnected. Outdoor unit’s circuit board is faulty.
23Service valve is closed. Compressor output is open phase. Electronic expansion valve is faulty. Refrigerant is insufficient.
27Outdoor fan motor is faulty. Connector connections are poor. Outdoor unit’s circuit board is faulty.
29Power supply construction is defective. Outdoor unit’s circuit board is faulty.
31Overcharge. Compressor lock.
32Overcharge. Compressor lock.
33Overcharge. Compressor lock.
34Overcharge. Compressor lock.
35Overcharge. Compressor lock.
36Overcharge. Compressor lock.
37Overcharge. Compressor lock.
41Overcharge. Compressor lock. Overload operation.
42Overcharge. Compressor lock. Overload operation.
43Overcharge. Compressor lock. Overload operation.
44Overcharge. Compressor lock. Overload operation.
45Overcharge. Compressor lock. Overload operation.
46Overcharge. Compressor lock. Overload operation.
50Refrigerant is insufficient. Discharge pipe sensor is faulty. Service valve is closed.
51Cooling Problem.
60Power supply is faulty. Power supply cables and signal lines are improperly wired. Indoor or outdoor unit circuit board is faulty.
61Connection lines between the indoor and outdoor units are faulty. Indoor or outdoor unit circuit boards are faulty.
62Indoor or outdoor unit circuit boards are faulty. Noise is causing faulty operation.
71Compressor is faulty. Compressor output is open phase. Electronic expansion valve is faulty. Overload operation Outdoor unit circuit board is faulty.
72Compressor is faulty. Compressor output is open phase. Electronic expansion valve is faulty. Overload operation Outdoor unit circuit board is faulty.
73Compressor is faulty. Compressor wiring is disconnected. Compressor wiring is short circuited. Outdoor unit’s circuit board is faulty.
74Compressor is faulty. Compressor wiring is disconnected. Compressor wiring is short circuited. Outdoor unit’s circuit board is faulty.
75Compressor is faulty. Compressor wiring is disconnected. Compressor wiring is short circuited. Outdoor unit’s circuit board is faulty.
76Compressor is faulty. Compressor wiring is disconnected. Compressor wiring is short circuited. Outdoor unit’s circuit board is faulty.
80Fan motor is faulty. Connector connections are poor. Indoor unit circuit board is faulty.
81Discharge pipe sensor wire is disconnected. Connector connections are poor.
82Indoor heat exchanger sensor wire is disconnected. Connector connections are poor.
83Outdoor heat exchanger sensor wire is disconnected. Connector connections are poor.
84High humidity condition. Humidity sensor is faulty.
85Indoor unit fan speed drops. Indoor heat exchanger sensor short circuit.
86Heating overload. Indoor unit fan speed drops. Indoor heat exchanger sensor short circuit
87Refrigerant is insufficient. Discharge pipe sensor is faulty. Service valve is closed.
88Service valve is closed. Refrigerant is insufficient.

VRF Inverter Multi System

KX4 series and KX6 series

MHI VRF Inverter Multi System Error Codes
Error CodesCause
E1Remote controller communication error. Possible Cause: Anomalous communication circuit between remote controller and indoor unit, Noise.
E2Duplicated indoor unit addressing more than 49 units connected. Possible Cause: Number of connected indoor units exceeds the limitation, Duplicated indoor unit address, Indoor PCB anomaly.
E3Outdoor unit signal line error. Possible Cause: Power is not suppied to outdoor unit, Unmatch of pairing between indoor and outdoor units, Indoor PCB anomaly, Outdoor control PCB anomaly, Missing local wiring.
E5Communication error during operation. Possible Cause: Unit address No. setting error, Remote control wires broken, Poor connection/ disconnection of remote controller wires, Indoor control PCB anomaly, Noise.
E6Indoor heat exchanger temp. sensor anomaly (Thi-R). Possible Cause: Sensor anomaly, Poor connection, Indoor control PCB anomaly.
E7Indoor return air temp. sensor anomaly (Thi-A). Possible Cause: Sensor anomaly, Poor connection, Indoor control PCB anomaly.
E9Drain trouble. Possible Cause: Blocked drain, Drain pump anomaly, Float switch anomaly, Indoor contyrol PCB anomaly.
E10Excessive number of indoor units by controlling one renote controller. Possible Cause: Excessive number of indoor units connected (more than 17 units), Remote controller anomaly.
E11Address setting error (setting with remote controller). Possible Cause: When plural indoor units are connected, do not use remote controller address setting method.
E12Address setting error by mixed setting method. Possible Cause: The atomatic setting and manual setting mixed in the address setting method for indoor units.
E16Indoor fan motor anomaly. Possible Cause: Fan motor anomaly, Poor connection, Indoor PCB anomaly.
E18Address setting error of master and slave indoor remote controller. Possible Cause: Remote controller SW address setting error of master and slave indoor units.
E19Indoor unit operation check, drain motor check mode anomaly. Possible Cause: Mistake in SW7-1 setting due to forgetting to turn OFF SW7-1 after indoor operation check finished.
E20Indoor fan motor rotationtion speed anomaly (FDT, FDTC, FDK, FDTW). Possible Cause: DC fan motor revolution speed anomaly, Indoor power (control) PCB anomaly, Foreign material at rotational area of fan motor.
E21FDT Limit switch is not activated. Possible Cause: Limit switch on the panel anomaly, Anomalous mounting position of gille, Connector CNV loose.
E22Wrong connection with Outdoor unit. Possible Cause: Unmatched pairing of indoor and outdoor unit, Indoor control PCB anomaly, Outdoor control PCB anomaly.
E28Remote controller temp. sensor anomaly (Thc). Possible Cause: Remote controller temp. sensor anomaly, Poor connection, Remote controller PCB anomaly.
E30Unmatch connection of indoor and outdoor unit. Possible Cause: Indoor control PCB anomaly, Outdoor control PCB anomaly.
E31Duplicated outdoor unit address No.. Possible Cause: Mistake in the address setting of outdoor units, More than 129 indoor units connected, No setting of Master/Slave setting switch for combination use.
E32Open L3 phase on power supply at primary side. Possible Cause: Anomalous power supply at primary side, Outdoor control PCB anomaly.
E361.Discharge pipe temp. sensor anomaly, Outdoor control PCB anomaly, Short circuit of airflow, Insufficient airflow volume, Insufficient amount of refrigerant, SV1, 2 (liquid refrigerant by pass valve) anomaly. 2. Liquid flooding anomaly. Overcharging of refrigerant, Superheat control anomaly, Circuit of liquid refrigerant by pass anomaly, Discharge pipe temp. sensor anomaly, EEV indoor anomaly.
E37Outdoor heat exchanger temp. sensor (Tho-R) and subcooling coil temp. sensor (Tho-SC, -H) anomaly. Possible Cause: Broken sensor harness or the internal wire of sensing section, Poor connection, Outdoor contron PCB anomaly.
E38Outdoor air temp. sensor anomaly  (Tho-A). Possible Cause: Broken sensor harness or the internal wire of sensing section, Poor connection, Outdoor contron PCB anomaly.
E39Discharge pipe temp. sensor anomaly (Tho-D1, D2). Possible Cause: Broken sensor harness or the internal wire of sensing section, Poor connection, Outdoor contron PCB anomaly.
E40High pressure anomaly (63H1-1,2 activated). Possible Cause: Disconnection of high pressure switch connector, High pressure sensor anomaly, High pressure switch anomaly, Short circuit of airflow at condenser, Close service valve.
E41 Power transistor overheat. Possible Cause: Power transistor anomaly, Power transistor temp. sensor anomaly, Improperly fixing of power transistor to radiator fin, Inverter PCB anomaly, Outdoor fan motor anomaly, Cooling fan motor for inverter anomaly, Inadequate installation space of outdoor unit.
E51Power transistor overheat. Possible Cause: Power transistor anomaly, Power transistor temp. sensor anomaly, Improperly fixing of power transistor to radiator fin, Inverter PCB anomaly, Outdoor fan motor anomaly, Cooling fan motor for inverter anomaly, Inadequate installation space of outdoor unit.
E42Current cut (CM1, CM2). Possible Cause: Compressor anomaly, Leakage of refrigerant, Power transistor module anomaly, Anomalous power supply for inverter PCB, Outdoor fan motor anomaly.
E43Excessive number of indoor units connected, excessive total capacity. Possible Cause: Mistake in setting of indoor/outdoor unit addresses, Mistake in signal wire connection.
E45Communication error between inverter PCB and outdoor control PCB. Possible Cause: Signal wire anomaly, Outdoor control PCB anomaly, Inverter PCB (INV1,2) anomaly, Rush current prevention resistor anomaly.
E46Mixed address setting methods conexistent in same network. Possible Cause: Mistake in the address setting, Mistake in the connection of signal wire.
E48Outdoor DC fan motor anomaly. Possible Cause: Outdoor fan motor anomaly, Poor connection, Inverter PCB anomaly, Outdoor control PCB anomaly.
E49Low pressure anomaly. Possible Cause: Low pressure sensor anomaly, Service valves closed, EEV anomaly (EEV closed), Insufficient refrigerant amount, Clogging at EEV or strainer.
E53Suction pipe temp. sensor anomaly (Tho-S). Possible Cause: Broken sensor harness or the internal wire of sensing section, Poor connection, Outdoor contron PCB anomaly.
E54High pressure sensor anomaly (PSH)/ Low pressure sensoe anomaly (PSL). Possible Cause: Broken sensor harness, Disconnection of sensor, Sensor (PSH, PSL) anomaly, Outdoor control PCB anomaly, Anomalous installation condition, Insufficient airflow volume, Excessive or insufficient refrigerant amount.
E55Under-dome temp. sensor anomaly (Tho-C1, C2). Possible Cause: Broken sensor harness or the internal wire of sensing section, Poor connection, Outdoor contron PCB anomaly.
E56Power transistor temp. senser anomaly (Tho-P1, P2). Possible Cause: Broken sensor harness or the internal wire of sensing section, Poor connection, Outdoor contron PCB anomaly.
E58Anomalous compressor by loss of synchronism. Possible Cause: Insufficient time elapsed after the power supplied before compressor startup, Startup compressor without crankcase heater ON, Compressor anomaly.
E59Compressor startup failure (CM1, CM2). Possible Cause: Anomalous voltage of power supply, Anomalous components for refrigerant circuit, Inverter PCB anomaly, Loose connection of connector or cable, Compressor anomaly (Motor or bearing)
E60Rotor position detection failure (CM1, CM2). Possible Cause: Compressor anomaly, Inverter PCB anomaly, Anomaly of power supply.
E61Communication error between the master unit and slave units. Possible Cause: Signal wire anomaly, Outdoor control PCB anomaly, Inverter PCB (INV1,2) anomaly, Rush current prevention resistor anomaly.
E63Emergency stop. Possible Cause: Factors for emergency stop.
E75Central control communication error. Possible Cause: Poor connection, faulty controller.
Mitsubishi Heavy Industries Wired remote control
Mitsubishi Heavy Industries Wired Remote Control

Self-diagnosis Table

When this air conditioner performs an emergency stop, the reason why the emergency stop occurred is displayed by the flashing of display lights. If the air conditioner is operated using the remote control 3 minutes or more after the emergency stop, the trouble display stops and the air conditioner resumes operation.

Error CodesMeaning
E1The wired remote control wire Y is open. The wired remote control wires X and Y are reversely connected. Noise is penetrating the wired remote control lines. The wired remote control or indoor control PCB is faulty. (The communications circuit is faulty.)
E3-E5When there is no signal between the indoor unit’s board and outdoor unit’s board for 10 seconds or longer (when the power is turned on), or when there is no signal for 7 minute 35 seconds or longer (during operation)(the compressor is stopped).
E16When conditions for turning the indoor unit’s fan motor on exist during air conditioner operation, an indoor unit fan motor speed of 300 rpm or lower is measured for 30 seconds or longer. (The air conditioner stops.)
E38When an outdoor temperature sensor wire disconnection is detected while the power is turned on or after the outdoor unit’s speed has continued at 0rps or higher for 2 minutes. (If a temperature of –55ºC or lower is detected for 20 seconds, it is judged that wire is disconnected.) (The compressor is stopped.)
E37When a heat exchanger sensor wire disconnection is detected while the power is turned on or after the outdoor unit’s speed has continued at 0rps or higher for 2 minutes. (If a temperature of –55ºC or lower is detected for 20 seconds, it is judged that wire is disconnected.) (The compressor is stopped.)
E39When a discharge pipe sensor wire disconnection is detected after the outdoor unit’s speed has continued at 0rps or higher for 10 minutes. (If a temperature of –25ºC or lower is detected for 20 seconds, it is judged that wire is disconnected.) (The compressor is stopped.)
E42The inverter output current (compressor motor current) exceeds the set value during compressor start. (The air conditioner stops.)
E59When there is an emergency stop caused by trouble in the outdoor unit, or the input current value is found to be lower than the set value. (The air conditioner stops.)
E58When the inverter command speed is lower than the set value and the current safe has operated. (the compressor stops)
E51When the power transistor is judged breakdown while compressor starts. (The compressor is stopped.)
E36When the value of the discharge pipe sensor exceeds the set value. (The air conditioner stops.)
E48When the outdoor unit’s fan motor speed continues for 30 seconds or longer at 75 rpm or lower. (3 times) (The air conditioner stops.)
E35When the value of the outdoor heat exchanger sensor exceeds the set value.
E60If the compressor motor’s magnetic pole positions cannot be correctly detected when the compressor starts. (The air conditioner stops.)
E47When the wrong voltage connected for the power supply. When the outdoor control PCB is faulty
Mitsubishi heavy industries air conditioner timer light flashing
Mitsubishi heavy industries air conditioner timer light flashing
Mitsubishi heavy industries air conditioner timer light flashing
Mitsubishi heavy industries air conditioner timer light flashing

Stop Codes Table

Assignment of error codes and stop codes is done in common for all models

RUN-TIMER lightCause
OFF-OFF0-Normal
OFF-5 time flash05-Can not receive signals for 35 seconds (if communications have recovered). Power supply is faulty. Power supply cables and signal lines are improperly wired. Indoor or outdoor unit circuit boards are faulty. When 35 seconds passes without communications signals from either the outdoor unit or the indoor unit being detected correctly.
3 time flash-5 time flash35-Cooling high pressure control. Cooling overload operation. Outdoor unit fan speed drops. Outdoor heat exchanger sensor is short circuit. When the outdoor heat exchanger sensor's value exceeds the set value.
3 time flash-6 time flash36-Compressor overheat (115˚C). Refrigerant is insufficient. Discharge pipe sensor is faulty. Service valve is closed. When the discharge pipe sensor's value exceeds the set value.
3 time flash-7 time flash37-Outdoor heat exchanger sensor is abnormal. Outdoor heat exchanger sensor wire is disconnected. Connector connections are poor. When a temperature of –55˚C or lower is sensed continuously for 20 seconds while the power is turned on or after the outdoor unit's speed has continued at 0rps or higher for 2 minutes (the compressor stops).
3 time flash-8 time flash38-Outdoor air temperature sensor is abnormal. Outdoor air temperature sensor wire is disconnected. Connector connections are poor. When a temperature of –55˚C or lower is sensed continuously for 20 seconds while the power is turned on or after the outdoor unit's speed has continued at 0rps or higher for 2 minutes (the compressor stops).
3 time flash-9 time flash39-Discharge pipe sensor is abnormal (anomalous stop). Discharge pipe sensor wire is disconnected. Connector connections are poor. When a temperature of –25˚C or lower is sensed continuously for 20 seconds after the outdoor unit's speed has continued at 0rps or higher for 10 minutes (the compressor stops).
4 time flash-2 time flash42-Current cut. Compressor lock. Compressor wiring short circuit. Compressor output is open phase. Outdoor unit's circuit board is faulty. Service valve is closed. Electronic expansion valve is faulty. Compressor is faulty. Compressor start fails 42 times in succession and the reason for the final failure is current cut.
4 time flash-7 time flash47-Active filter voltage error. Defective active filter. When the wrong voltage connected for the power supply. When the outdoor control PCB is faulty
4 time flash-8 time flash48-Outdoor unit's fan motor is abnormal. Outdoor fan motor is faulty. Connector connections are poor. Outdoor unit's circuit board is faulty. When a fan speed of 75 rpm or lower continues for 30 seconds or longer.
5 time flash-1 time flash51-Short circuit in the power transistor (high side) Current cut circuit breakdown. Outdoor unit's circuit board is faulty. Power transistor is damaged. When it is judged that the power transistor was damaged at the time the compressor started.
5 time flash-7 time flash57-Refrigeration cycle system protective control. Service valve is closed. Refrigerant is insufficient. When refrigeration cycle system protective control operates.
5 time flash-8 time flash58-Current safe. Refrigerant is overcharge. Compressor lock. Overload operation. When there is a current safe stop during operation.
5 time flash-9 time flash59-Compressor wiring is unconnection Voltage drop Low speed protective control. Compressor wiring is disconnected. Power transistor is damaged. Power supply construction is defective. Outdoor unit's circuit board is faulty. When the current is 1A or less at the time the compressor started. When the power supply voltage drops during operation. When the outdoor unit's speed is lower than 26 rps for 60 minutes.
6 time flash-OFF60-Rotor lock. Compressor is faulty. Compressor output is open phase. Electronic expansion valve is faulty. Overload operation. Outdoor unit's circuit board is faulty. After the compressor starts, when the compressor stops due to rotor lock.
6 time flash-1 time flash61-Connection lines between the indoor and outdoor units are faulty. Connection lines are faulty. Indoor or outdoor unit circuit boards are faulty. When 10 seconds passes after the power is turned on without communications signals from the indoor or outdoor unit being detected correctly.
6 time flash-2 time flash62-Serial transmission error. Indoor or outdoor unit circuit boards are faulty. Noise is causing faulty operation. When 7 minute 35 seconds passes without communications signals from either the outdoor unit or the indoor unit being detected correctly.
8 time flash-OFF80-Indoor unit's fan motor is abnormal. Indoor fan motor is faulty. Connector connections are poor. Indoor unit's circuit board is faulty. When the indoor unit's fan motor is detected to be running at 300 rpm or lower speed with the fan motor in the ON condition while the air conditioner is running.
8 time flash-2 time flash82-Indoor heat exchanger sensor is abnormal (anomalous stop). Indoor heat exchanger sensor wire is disconnected. Connector connections are poor. When a temperature of –28˚C or lower is sensed continuously for 40 minutes during heating operation. (the compressor stops).
8 time flash-4 time flash84-Anti-condensation control. High humidity condition. Humidity sensor is faulty. Anti-condensation prevention control is operating.
8 time flash-5 time flash85-Anti-frost control. Indoor unit fan speed drops. Indoor heat exchanger sensor is broken wire. When the anti-frost control operates and the compressor stops during cooling operation.
8 time flash-6 time flash86-Heating high pressure control. Heating overload operation. Indoor unit fan speed drops. Indoor heat exchanger sensor is short circuit. When high pressure control operates during heating operation and the compressor stops.

Troubleshooting

TroubleSolution
The unit does not restart immediately after you have stopped it.Restart is blocked for 3 minutes after you have stopped the operation to protect the unit. The three-minute protection timer in the microcomputer automatically starts it up again.
Airflow is not blown out when starting the HEATING operation.Airflow has stopped to prevent blowing out of cold air until the indoor heat exchanger has warmed up.
Airflow is not blown out for 5 to 15 min. or blown out not warm wind for a moment at HEATING operation.When outdoor temperature is low and humidity is high, the unit sometimes performs defrosting automatically. Please wait. During defrosting, water or steam may escape from the outdoor unit.
Airflow is not blown out when starting the DRY operation.The indoor fan may stop to prevent re-evaporation of dehumified moisture and to save energy.
Some steam escapes during COOL operation. This may occur if the room's temperature and humidity are very high. It disappears as soon as the temperature and humidity decrease.
There is a slight smell.Air blown out during operation may smell. This is caused by tobacco or cosmetics adhering to the unit.
You hear a slight gurgling sound.This is caused by refrigerating liquid moving within the unit.
You hear a slight cracking sound.This is caused by heat expansion or contraction.
You hear a hissing or clicking sound.This is caused by the operation of the refrigerant control valves or electric components.
After a power cut, the unit does not restart even if power has been restored.If the auto restart function is not set, the unit will not restart automatically. Use the remote control to start the operation again.
Remote control signals are not received.Remote control signals may not be received if the signal receiver on the air-conditioner is exposed to direct sunlight or other bright light. If so, cut out the sunlight or reduce the other light.
Moisture may form on the air outlet grills.If the unit is operated for a long time in high humidity, moisture may form on the air outlet grills and start dripping.
Whistling noise is heard from the outdoor unit.The noise means that the revolution speed of the compressor is increasing or decreasing.
RUN light stays on even though operation was stopped.The RUN light illuminates during CLEAN operation. Run light turns off when CLEAN operation ends.

Mitsubishi Heavy Industries AC Manual PDF

Mitsubishi AC Error Codes

Danny Reese


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31 thoughts on “Mitsubishi Heavy Industries AC Error Codes (Simple Solutions)”

  1. I have bought one new board for outer unit and same has been fixed. But I found the timer light blinks continuously. can you help me?

    Reply
  2. Hai..
    After checking the unit of mitsubishi inverter split wall indor model SRK 10YN,I found the first 4 times lamps and 6 times continous lights,the indoor fan motor still working but the outdoor unit did not work either,what cause a damage?

    Reply

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