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Mitsubishi Split system troubleshooting

Even if these items are checked, when the unit does not recover from the trouble, stop using the air conditioner and consult your specialist.

Indoor unit

The unit cannot be operated.

  • Is the breaker turned on?
  • Is the power supply plug connected?
  • Is the ON timer set?

All LED lamps on the indoor unit are blinking.

  • Are the horizontal vanes installed correctly?

The horizontal vane does not move.

  • Are the horizontal vane and the vertical vane installed correctly?
  • Is the fan guard deformed?

The unit cannot be operated for about 3 minutes when restarted.

  • This protects the unit according to instructions from the microprocessor. Please wait.

Mist is discharged from the air outlet of the indoor unit.

  • The cool air from the unit rapidly cools moisture in the air inside the room, and it turns into mist.

The swing operation of the HORIZONTAL VANE is suspended for a while, then restarted.

  • This is for the swing operation of the HORIZONTAL VANE to be performed normally.

The airflow direction changes during operation. The direction of the horizontal vane cannot be adjusted with the remote controller.

  • When the unit is operated in COOL or DRY mode, if the operation continues with air blowing down for 0.5 to 1 hour, the direction of the airflow is automatically set to a horizontal position to prevent water from condensing and dripping.
  • In the heating operation, if the airflow temperature is too low or when defrosting is be- ing done, the horizontal vane is automatically set to a horizontal position.

The operation is stopped for about 10 minutes in the heating operation.

  • Defrosting of the outdoor unit is being done.
  • Since this is completed in max.10 minutes, please wait. (When the outside temperature is too low and humidity is too high, frost is
  • formed.)

The unit starts operation by itself when the main power is turned on, though it isn’t operated with the remote controller.

These models are equipped with an auto-restart function. When the main power is turned off without stopping the unit with the remote controller and is turned on again, the unit starts operation automatically in the same mode like the one set with the remote controller just before the shutoff of the main power. Refer to “Auto restart function”

The indoor unit discolors over time.

Although plastic turns yellow due to the influence of some factors such as ultraviolet light and temperature, this has no effect on the product functions.

Mitsubishi Multi-System troubleshooting

The indoor unit which is not operating becomes warm and a sound, similar to water flowing, is heard from the unit.

A small amount of refrigerant continues to flow into the indoor unit even though it is not operating.

When the heating operation is selected, the operation does not start right away.

When the operation is started during defrosting of the outdoor unit is done, it takes a few minutes (max. 10 minutes) to blow out warm air.

Outdoor unit

The fan of the outdoor unit does not rotate even though the compressor is running. Even if the fan starts to rotate, it stops soon.

When the outside temperature is low during cooling operation, the fan operates intermittently to maintain sufficient cooling capacity.

Water leaks from the outdoor unit.

  • During COOL and DRY operations, pipe or pipe connecting sections are cooled and this causes water to condense.
  • In the heating operation, water condensed on the heat exchanger drips down.
  • In the heating operation, the defrosting operation makes water frozen on the outdoor unit melt and drip down.

White smoke is discharged from the outdoor unit.

In the heating operation, the vapor generated by the defrosting operation looks like white smoke.

Air Conditioner does not cool/heat

The room cannot be cooled or heated sufficiently.

  • Is the temperature setting appropriate?
  • Is the fan setting appropriate? Please change the fan speed to a higher setting.
  • Are the filters clean?
  • Is the fan or heat exchanger of the indoor unit clean?
  • Are there any obstacles blocking the air inlet or outlet of the indoor or outdoor unit?
  • Is a window or door open?

The room cannot be cooled sufficiently.

  • When a ventilation fan or a gas cooker is used in a room, the cooling load increases, resulting in an insufficient cooling effect.
  • When the outside temperature is high, the cooling effect may not be sufficient.

The room cannot be heated sufficiently.

When the outside temperature is low, the heating effect may not be sufficient.

Air does not blow out soon in the heating operation.

Please wait as the unit is preparing to blow out warm air.

The air from the indoor unit smells strange.

  • Are the filters clean?
  • Is the fan or heat exchanger of the indoor unit clean?
  • The unit may suck in an odor adhering to the wall, carpet, furniture, cloth, etc., and blow it out with the air.

In the following cases, stop using the air conditioner and consult your dealer.

  • When water leaks or drips from the indoor unit.
  • When the upper operation indicator lamp blinks.
  • When the breaker trips frequently.
  • The remote control signal is not received in a room where an electronic ON/OFF type fluorescent lamp (inverter-type fluorescent lamp, etc.) is used.
  • Operation of the air conditioner interferes with radio or Tv reception. An amplifier may be required for the affected device.
  • When an abnormal sound is heard.

Don’t let a broken AC ruin your fun. Contact us now and get a cool and comfortable home, guaranteed! Our team of electricians and HVAC professionals is ready to help 24/7.

So, pick up the phone and dial our number for fast, reliable ABC service.”