Can I fix Mitsubishi Electric code P5 myself?

Start with these safe checks: Turn the system off. Look for water dripping from the indoor unit or a full condensate pump reservoir. If a condensate pump is plugged in separately, make sure it has power and its outlet tube isn't clogged. Drain pump and float switch repairs inside the unit are for an HVAC technician.

When should I call a technician for code P5?

Drain pump and float switch repairs inside the unit are for an HVAC technician. Don't open the sealed refrigerant system, cut or braze lines, or add refrigerant. That needs an EPA-certified technician. Turn power off at the breaker or disconnect before opening any panel, and leave capacitors, compressors and control boards to a pro: they can hold a dangerous charge even with the power off.

Mitsubishi Electric Mini-Split Error Code P5 / PA / P4: Drain pump…

What P5 means

A drain problem: P5 is a drain pump error, PA is a forced compressor stop due to a water leakage abnormality, and P4 means the float switch connector is open.

Also shown as: PA, P4, 4 blinks, 5 blinks, depending on the model.

Likely causes

Clogged condensate drain or pump
Drain pump failure
Float switch disconnected

Safe first checks

Turn the system off. Look for water dripping from the indoor unit or a full condensate pump reservoir.
If a condensate pump is plugged in separately, make sure it has power and its outlet tube isn't clogged.

When to stop

Drain pump and float switch repairs inside the unit are for an HVAC technician.

Checked against: Mitsubishi Electric, Mr. Slim indoor/outdoor unit malfunction-diagnosis check codes (2024-11-18). Codes can differ by model and year, so confirm with your owner's manual.