BoilerFaultCodes On Off * Off High
Boiler Fault Code On Off * Off
Also written as ONOFFOFF — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code On Off * Off 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 boiler has detected that it is getting too hot and has automatically shut itself down to prevent damage. (As reported on Potterton Promax FSB 30HE)
Pick your boiler brand for the On Off * Off fix
Source
Information for the On Off * Off 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