Mitsubishi Electric P5 Error Code: Drain pump error (water leakage abnormality)
Updated October 2026 · Sourced from Mitsubishi Electric documentation
🧭 Check a few things first
The indoor unit reports a drain pump error caused by a water leakage abnormality.
Is it safe to keep running? Check the steps below first. A technician should clear the drain problem and check the pump and float switch.
P5 at a glance
| Code / how it shows | Meaning | Applies to |
|---|---|---|
| P5 Wireless remote: the OPERATION INDICATOR lamp flashes 5 times in a self-check; wired remote shows the code | Drain pump error (water leakage abnormality) | 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.
- Turn the unit off and look for water on the floor or dripping from the unit.
- Do not keep running the unit if water is leaking.
🛑 Stop and call a licensed pro if
- A technician should clear the drain problem and check the pump and float switch.
- 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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