Mitsubishi Electric P6 error code: coil freeze or overheat protection

What Does Error P6 Mean?

Mitsubishi Electric assigns P6 to a freezing or overheating protection trip at the indoor coil. In cooling the coil pipe temperature fell far enough to risk ice, and in heating it climbed too high, so the control stopped the compressor. It points at airflow across the coil, the coil thermistor, or the refrigerant condition rather than at one named part. Applies to: Mitsubishi Electric Mr Slim and M-Series systems that publish the P-series protection table This reading follows Mitsubishi Electric literature for the Mr Slim and M-Series families that publish a P-series protection table. Other Mitsubishi Electric ranges, and Mitsubishi Heavy Industries equipment, use different code tables, so match the indoor and outdoor model numbers first. Owner-safe checks: With the system off, remove and clean the indoor filters, dry them fully, refit them, and confirm nothing blocks the intake or outlet of the indoor unit. | Note whether P6 happened in cooling or heating, whether the coil was frosted, and whether airflow felt weak beforehand. Qualified technician: Checking refrigerant charge, cleaning the indoor coil or blower wheel, and measuring or replacing the coil thermistor require a qualified technician with gauges.