How much does it cost to fix boiler error code 231?

Typical repair cost for the boiler 231 fault is £100-200 including labour.

231 Medium

Boiler Fault Code 231

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code 231 appears across 1 boiler brand and 4 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has detected a brief loss of electricity or a unstable power supply, causing it to shut down for protection. (As reported on Worcester Bosch 24/28/35 CDi MkII)

Pick your boiler brand for the 231 fix

Worcester Bosch 231 4 models

Source

Information for the 231 fault code is sourced from the official service / installation manual for each model that displays it. Read more about how we source fault codes →

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026