BoilerFaultCodes b0 High
Boiler Fault Code b0
Also written as B0 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code b0 appears across 1 boiler brand and 9 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler has stopped working because it has detected a technical fault with the sensor that monitors the heat of the exhaust gases. (As reported on Viessmann Vitodens 333)
Pick your boiler brand for the b0 fix
Source
Information for the b0 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