BoilerFaultCodes b6 High
Boiler Fault Code b6
Also written as B6 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code b6 appears across 1 boiler brand 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 internal computer is experiencing a communication error, meaning it has lost track of its own settings and cannot safely operate. (As reported on Worcester Bosch Highflow 550 CDi)
Pick your boiler brand for the b6 fix
Source
Information for the b6 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