What does error code P1 mean on a Mitsubishi Electric mini-split?

Intake (room) sensor error. The intake air (room temperature) sensor has an error.

Can I fix Mitsubishi Electric code P1 myself?

Start with these safe checks: Turn the system off at the breaker for a few minutes and back on. If P1 returns, call an HVAC technician.

When should I call a technician for code P1?

If P1 returns, call 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 P1 / 1 blink: Intake…

What P1 means

The intake air (room temperature) sensor has an error.

Also shown as: 1 blink, depending on the model.

Likely causes

Sensor or connection fault

Safe first checks

Turn the system off at the breaker for a few minutes and back on.

When to stop

If P1 returns, call 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.