Bosch H01 (5508)

Critical

Compress — High pressure guard MR1 tripped.

Bosch H01 (5508): High pressure guard MR1 tripped. This fault typically halts operation and needs immediate attention.

Possible causes

Heat carrier flow too low.
Pressure guard faulty or EEV stays closed.

Check steps

Open/bleed circuit, increase flow.
Check MR1 wiring & EEV function.

Affected parts

Hochdruckwächter MR1
Expansionsventil

Safety note

HP side of refrigerant circuit – qualified only.

Source: Bosch resmi servis kılavuzu — Alarm List 8754, code 5508, Display Code H01, Customer: "Alarm Z1 MR1 High pressure alarm — Alarm if error code 5507 is registered more than 2 times within 3 h, or if the circuit for the high pressure guard is continuously open for 15 minutes."

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

Look up in Enthalio →

Related fault codes

No EMS BUS communication / internal connectionA11 Booster heater limiter (STB) or pressure switcA01 (5246) Hot gas temperature too high (TR6 > 110–120H01 (5311) Z1 phase monitor tripped: one or more supply-vA01 (5273) Compressor control failure – not running / locA01 (5350) No communication via EMS BUS.A11 (1010)