BoilerFaultCodes 257 High
Boiler Fault Code 257
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 257 appears across 2 boiler brands and 6 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler's main control computer is experiencing a temporary glitch or internal error, which has caused it to pause its normal operation as a safety precaution. (As reported on Worcester Bosch Greenstar 2000)
Pick your boiler brand for the 257 fix
Source
Information for the 257 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 31 August 2026