Troubleshooting AC
Troubleshooting: Wall-mounted Air Conditioner
Troubleshooting: Wall-mounted Air Conditioner
Worried about what to do when your air conditioner is not working properly? You can identify the issues before calling in a service professional. Mitsubishi Electric air-conditioners are designed for your convenience even at an inconvenient time, and the units will display a code for you to see the error diagnosis. By better understanding the possible causes, our air-conditioners make it easier for you to communicate with your dealer or technician.
Flashing Light on Upper / Left Operation Indicator Lamp
When the indoor unit is operating and has detected an abnormality, the indoor fan motor will automatically switch OFF, and the upper or left operation indicator lamp will flash.
Indoor unit failure mode table
- First, check the indoor unit’s upper or left operation indicator lamp to see if it is flashing ON and OFF. If the indicator lamp is flashing, it is indicating an abnormality. To identify the error, count how many times the indicator lamp flashed between the delay time.
- Make sure your horizontal vane is correctly installed. Loose vane installation may also be a reason for the indicator lamp to flash.
| Upper Lamp Of Operation Indicator Lamp | Abnormal point (Failure mode) |
Condition | ||||
|---|---|---|---|---|---|---|
| Not lighted | Normal | None (Normal) | ||||
| 1-time flash every 0.5 second | Room temperature thermistor | Room coil temperature thermistor is short/open circuit | ||||
| 2-time flash, 2.5 second OFF | Indoor coil thermistor | Indoor coil temperature thermistor is short/open circuit | ||||
| 3-time flash, 2.5 second OFF | Serial signal | Rotation frequency feedback signal is not emitted during the indoor fan operation | ||||
| 4-time flash, 2.5 second OFF (Inverter only) | Indoor fan motor | Indoor PCB failure | ||||
| 5-time flash, 2.5 second OFF (Inverter only) | Indoor control system | Compressor stops after 3 times of over-current / start-up failure protection within 1 minute after start-up | ||||
| 6-time flash, 2.5 second OFF (Inverter only) | Outdoor thermistors | Outdoor thermistor is short / open circuit | ||||
| 7-time flash, 2.5 second OFF (Inverter only) | Outdoor control system | Indoor / outdoor PCB failure | ||||
| 11-time flash, 2.5 second OFF | Indoor fan motor | Rotation frequency feedback signal is not emitted during 12 seconds the indoor fan operation | ||||
| 14-time flash, 2.5 second OFF | Refrigerant circuit |
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Error Codes Display on Remote Controller
The error code will be displayed on the remote controller while the upper operation indicator lamp on the indoor unit is blinking. Follow the procedure below to check the error code.
NOTE:
- Press any button to cancel the error code display mode of the remote controller.
- The error code may not appear if the operation indicator lamp is not blinking.
Displaying the error code
- Make sure the handheld remote controller is powered off.
- Get nearer in front of the indoor unit (within 2 m), point the remote controller at the receiving section of the indoor unit, and press and hold the small “CHECK” button with a fine-tipped object.
- While pressing and holding the “CHECK” button, keep pointing the remote controller at the receiving section of the indoor unit until you hear a beep and see the error code (2 digits) on the controller’s display.
- Check the error code table below to identify the issue.
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- If “–” appears on the display, it means the remote controller has not received the signal from the indoor unit. Press any button to cancel the error code display mode. Get closer to the indoor unit, and try again. If the remote controller is still unable to receive the signal, turn off noise sources (fluorescent lamp, TV, speakers, etc.) and try again.
- “00” appears on the display when there is no error.
- When an error code (other than “00”) appears on the display, the air-conditioner needs to be inspected and repaired. Stop using the air conditioner, turn off the breaker, and contact your dealer.
Download R32 Refrigerant Guidelines
Find out more about R32 Refrigerant air-conditioners through this in-depth document we have compiled for your reference.
Consult your dealer or technician about any major issues.
If your air-conditioner is diagnosed with a major issue (eg. refrigerant leak, damaged compressor, thermostat malfunction, etc.), contact your dealer, technician, or servicing person. The person servicing your unit should be a certified professional with the expertise to solve the issue. Trying to repair the air-conditioner on your own is not advisable. Check your air-conditioner warranty here.
