Hb High

Boiler Fault Code Hb

Also written as HB — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code Hb appears across 1 boiler brand and 1 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your heating system has shut down because it is struggling to circulate water properly while detecting very cold temperatures within the unit. (As reported on Ideal HP290)

Pick your boiler brand for the Hb fix

Ideal Hb 1 model

Source

Information for the Hb 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