BoilerFaultCodes 815 W/B High
Boiler Fault Code 815 W/B
Also written as 815WB — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 815 W/B appears across 1 boiler brand and 10 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler's temperature sensors are receiving conflicting or incorrect readings, causing the system to stop working correctly to protect itself. (As reported on Worcester Bosch Greenstar 8000 Life/Style)
Pick your boiler brand for the 815 W/B fix
Source
Information for the 815 W/B 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 27 April 2026