b30 High

Boiler Fault Code b30

Also written as B30 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code b30 appears across 4 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 has detected that water is heating up too quickly or not circulating properly through the system, causing it to shut down for safety. (As reported on Vokera Pinnacle)

Pick your boiler brand for the b30 fix

Atag b30 1 model Johnson Starley b30 3 models Remeha b30 2 models Vokera b30 1 model

Source

Information for the b30 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