What does a Mitsubishi aircon error code mean?

How a Mitsubishi aircon error code appears

Mitsubishi Electric aircon error codes point to the part the unit has flagged, such as a sensor, a fan motor, a control board or the link between indoor and outdoor units. Mitsubishi Electric's single and multi split error code sheet shows that wall-mounted split units report a fault as a count of blinks on the operation indicator lamp. Its Mr. Slim error code sheet shows that Mr. Slim units give a beep and blink count on wireless remotes and a check code, such as P5 or E6, on wired remotes.

If you are looking up a Mitsubishi Starmex error code, use the split sheet, which covers the Starmex inverter indoor models it lists. Each sheet lists its models, so check your indoor unit's model number against that list first. Whichever type you have, write down the code or blink count with the model number for your technician.

Wall-mounted split: blink patterns

On the Starmex inverter split indoor units listed on Mitsubishi Electric's split error code sheet, the blink pattern of the operation indicator lamp points to one of the fault areas below. For an indoor control system fault, the sheet says to replace the indoor control board. For an outdoor power system fault, it says to check the inverter or compressor and check the stop valve.

The exact blink count for each fault differs by model. Match your model number on the sheet first, then look up the count.

For blinking lamps more generally, see our guide to an aircon blinking light.

Mr. Slim ceiling units: check codes

Mitsubishi Electric's Mr. Slim error code sheet gives check codes for the Mr. Slim indoor units it lists. A wired remote shows the code itself. With a wireless remote, note the beep and blink count along with your model number.

If you see P5 or PA, switch the unit off at the remote and watch for dripping from the ceiling. Still choosing a unit type? See our comparison of ceiling cassette or wall-mounted units.

What you can check yourself

Mitsubishi Electric's FAQs give three checks. If the indoor unit has no power, check the power supply source for any trip. If cooling is poor, the air filters, line flow fan or cooling coil may be dirty. On a fan coil unit, two blinking lights can mean the safety switch beside the louvres is not locked in.

The steps below are practical guidance for a first check.

1. Switch off. Turn the aircon off at the remote, then at its isolator switch.
2. Reset a trip once only. If a switch has tripped, push it back up once. If it trips again straight away, leave it off and call a Licensed Electrician.
3. Clean the filters. Follow our guide on how to clean an aircon filter and let them dry fully before refitting.
4. Restart and note the pattern. Switch the isolator and the unit back on. If the code or blinking returns, write it down.

When to call a technician

Call a technician for any code that points to a control board, the compressor or inverter, a refrigerant leak or the drain pump. Call one too if the same code returns after one reset and clean filters, or if water keeps dripping from a ceiling unit.

Before you call, write down:

• The model number of the indoor unit
• The check code, or the blink or beep count
• What happened just before, such as a trip or dripping water
• Whether the code came back after one reset

The price depends on the fault and the work involved, so read our guide to aircon repair cost before you compare quotes.

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