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Mitsubishi Electric Air Conditioner PL Error Code
Refrigerant circuit abnormal. Here is what it means and how to clear it, easiest fix first.
The system has detected that its refrigerant circuit isn't behaving normally. Pinning down why requires a technician's checks of the refrigerant system.
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.
How to fix Mitsubishi Electric PL
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.
Stop if the code comes straight back
If PL reappears after the reset, switch the system off and leave it off rather than restarting it again and again. Repeated restarts against a protection fault can strain the compressor and other outdoor parts.
When to call a technician
Refrigerant circuit problems require a licensed technician. Don't open the refrigerant lines or add refrigerant.
Parts that commonly cause PL
- refrigerant piping
- 4-way valve
- expansion valve
Order parts by your exact model number so they fit.
Other Mitsubishi Electric air conditioner codes
- Blinking OPERATION lightWall unit's indicator light is flashing
- P1Room air temperature sensor fault
- P2 / P9Indoor coil temperature sensor fault
- P4 / P5Drain sensor or drain pump problem
- PAShut down to prevent a water leak
- P6Freeze or overheat protection
- P8Pipe temperature error
- PbIndoor fan motor error
- FbIndoor control board error
- E0-E5Wall controller communication error
- E6 / E7 / E9Indoor and outdoor units aren't communicating
- U1 / UdHigh pressure or overheat protection
- U2Discharge temperature too high or low refrigerant
- U3 / U4Outdoor temperature sensor fault
- U6 / UP / UFCompressor overcurrent
- U8Outdoor fan stopped
- U9 / UHPower supply or current sensor problem
Frequently asked questions
What does PL mean on a Mitsubishi Electric air conditioner?
The system has detected that its refrigerant circuit isn't behaving normally. Pinning down why requires a technician's checks of the refrigerant system.
Can I fix Mitsubishi Electric PL myself?
Only the basic checks. You can safely try the steps above, but PL usually points to a part or fault that needs a technician.
What if PL keeps coming back?
A code that returns after a reset and the checks above usually means a part is wearing out. Note when PL 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.