BoilerFaultCodes 354 High
Boiler Fault Code 354
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 354 appears across 2 boiler brands and 7 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler's computer has lost its internal safety settings for water pressure, which means it cannot accurately monitor the system and will prevent itself from firing. (As reported on Worcester Bosch 24/28/35 CDi MkII)
Pick your boiler brand for the 354 fix
Source
Information for the 354 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