Mitsubishi Electric P8 fault: what the code actually narrows down

What Does Error P8 Mean?

Mitsubishi Electric P8 reports an abnormal piping-temperature relationship. It can follow low refrigerant flow, a restricted circuit, a displaced or faulty thermistor, or crossed piping and wiring on some multi systems; P8 does not identify one failed part. Applies to: Mr Slim families covered by Mitsubishi Electric's P8 reference This interpretation is limited to Mitsubishi Electric systems included in the cited P8 reference. It does not apply to Mitsubishi Heavy Industries equipment, and the exact service sequence must be selected by the complete indoor and outdoor model numbers. Owner-safe checks: Photograph the full code and both model plates, then record the mode and elapsed run time when P8 returns. Qualified technician: Refrigerant measurements, thermistor testing, terminal checks, and correction of paired piping or wiring belong to qualified service personnel.