Mitsubishi Electric P6 Error Code: Freezing or overheating protection operation
Updated October 2026 · Sourced from Mitsubishi Electric documentation
🧭 Check a few things first
The unit reports that freezing or overheating protection operation has worked.
Is it safe to keep running? Check the steps below first. If P6 returns with clean filters and free airflow, a technician needs to check the refrigerant system.
P6 at a glance
| Code / how it shows | Meaning | Applies to |
|---|---|---|
| P6 Wireless remote: the OPERATION INDICATOR lamp flashes 6 times in a self-check; wired remote shows the code | Freezing or overheating protection operation | PLA-RP35/50/60/71/100/125/140BA ceiling cassette indoor units (Mr. Slim, OCH416 service manual) |
Check this first
Only steps a homeowner can do safely. Do not open electrical panels or the burner area.
- Check that the air filter is clean and nothing blocks the air intake or outlet.
- Turn the unit off for a while, then restart it.
🛑 Stop and call a licensed pro if
- If P6 returns with clean filters and free airflow, a technician needs to check the refrigerant system.
- Any code pointing to refrigerant, the compressor, high pressure or the outdoor unit board. Refrigerant work legally needs a certified technician.
- Burning smell, sparks, or a breaker that trips again after a reset.
- Water leaking from the indoor unit that does not stop after the drain is clear.
Safe first steps for any Mitsubishi Electric code
- Write down the exact code and how it shows (remote display or number of lamp blinks). Similar codes mean different things on different series.
- Turn the system off at the remote, switch off the breaker or disconnect for the unit, wait a few minutes, then turn it back on.
- Clean or replace the indoor unit air filters, and make sure nothing blocks the indoor or outdoor unit.
- Check that the condensate drain line is not blocked or kinked where you can see it.
- Replace the remote controller batteries if the display is dim or the unit does not respond.
Source: Mitsubishi Electric PLA-RP BA Service Manual OCH416 Rev. D, p.22. Codes are series-specific, so your unit's own manual is the final word. Reviewed October 2026.
Shaun Cain · Certified HVAC & Refrigeration Technician · Ask an HVAC technician
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