Mitsubishi Electric U2

Critical

Mr. Slim — High discharge temperature — compressor overheating.

Mitsubishi Electric U2: High discharge temperature — compressor overheating. This fault typically halts operation and needs immediate attention.

Possible causes

Low refrigerant.
Faulty thermistor.
High ambient/operating conditions.

Check steps

Check charge & superheat.
Measure discharge thermistor (TH4).
Check airflow/condenser.

Affected parts

Thermistor (TH4)
Kältemittel

Safety note

Hot discharge side & follow F-Gas.

Source: Mitsubishi Electric resmi servis kılavuzu — Same Mitsubishi Mr. SLIM official reference, 'Output pattern B' (errors detected by outdoor unit) table: 'U2 — Abnormal high discharging temperature/49C worked/insufficient refrigerant'. Also PUY-P/PUY-M outdoor board table: 'U2/U7 — Abnormality of comp. surface thermistor(TH32/3…

Reviewed by Anıl Güzeldemir — in the refrigeration machine room since 2006, developer of Enthalio.

Look up in Enthalio →

Related fault codes

Indoor/outdoor communication error.E6 Outdoor thermistor fault (open/short).U4 Pipe temperature error (often defrost/thermistP8 Intake (room) thermistor fault.P1 Pipe (liquid) thermistor fault.P2 Drain float switch / drain sensor fault.P4