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Mitsubishi Electric Air Conditioner P8 Error Code

Pipe temperature error. Here is what it means and how to clear it, easiest fix first.

P8
May need a pro

The indoor unit is seeing pipe temperatures it doesn't expect for the mode it's in, meaning the coil isn't getting as hot or cold as it should. Mitsubishi Electric does not give a single cause; the checks behind it involve the refrigerant circuit and sensors.

These check codes appear on wired wall controllers, mainly with P-series, Mr. Slim and ducted or ceiling units; wall-mounted M-series units (MSZ) usually report faults by blinking the OPERATION light instead. The meanings here come from Mitsubishi Electric's Mr. Slim code list for Singapore models, and they can differ by series and region, so check your manual. The exact checks behind P8 differ by model; your service manual lists them.

Safety first: unplug the air conditioner (or switch off its breaker) before touching filters, hoses or panels. If you smell burning or gas, or see water near the outlet, stop and call a professional.

How to fix Mitsubishi Electric P8

  1. Clean the filters

    Switch off the breaker, wash the indoor filters and refit them dry, since poor airflow can contribute.

  2. Reset the power at the breaker

    Switch off the breaker that feeds the air conditioner (some systems have separate breakers for the indoor and outdoor units, so switch off both). Wait about five minutes, switch the power back on and restart the unit to see if the code clears.

When to call a technician

If P8 comes back, a technician needs to check the refrigerant circuit. Refrigerant work is for licensed technicians only.

Parts that commonly cause P8

Order parts by your exact model number so they fit.

Other Mitsubishi Electric air conditioner codes

Frequently asked questions

What does P8 mean on a Mitsubishi Electric air conditioner?

The indoor unit is seeing pipe temperatures it doesn't expect for the mode it's in, meaning the coil isn't getting as hot or cold as it should. Mitsubishi Electric does not give a single cause; the checks behind it involve the refrigerant circuit and sensors.

Can I fix Mitsubishi Electric P8 myself?

Only the basic checks. You can safely try the steps above, but P8 usually points to a part or fault that needs a technician.

What if P8 keeps coming back?

A code that returns after a reset and the checks above usually means a part is wearing out. Note when P8 appears (which cycle, how often) and have your model number ready; it helps a technician bring the right part on the first visit.

Last reviewed 2026-10-19. Codes and steps can vary by model; check your owner's manual.

References