BoilerFaultCodes c OF Low
Boiler Fault Code c OF
Also written as COF — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code c OF 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 is currently set to a standby mode where the central heating function has been manually turned off at the controls. (As reported on Vokera Hydra)
Pick your boiler brand for the c OF fix
Source
Information for the c OF 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