Fault Codes / Bosch / 3121

Bosch 3121

High

Compress — Temperature limiter (heating circuit) triggered.

Bosch 3121: Temperature limiter (heating circuit) triggered. This fault noticeably affects operation.

Possible causes

Heating flow temp too high (e.g. floor).
Limiter/wiring faulty.

Check steps

Check max temperature & mixer.
Check temperature limiter & wiring.

Affected parts

Temperaturbegrenzer

Safety note

Hot water — scald risk.

Source: Bosch/IVT/Buderus Compress Wärmepumpe Alarm-Tabelle (lvisawo.fi/jseducation.se resmi servis kılavuzu aynası) — Buderus EMS Servicehandbuch: 'A31 3121 10 ... Temperaturbegrenzung ausgelöst — Anschlussklemme MC15 und MC16 nicht bestückt mit Brücke oder Temperaturbegrenzer.' Confirmed, exact match to app descript

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

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