BoilerFaultCodes 278 High
Boiler Fault Code 278
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 278 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 detected a communication failure with an internal sensor, meaning it cannot accurately monitor temperatures and has shut down for safety. (As reported on Worcester Bosch Greenstar Heatslave II)
Pick your boiler brand for the 278 fix
Source
Information for the 278 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