BoilerFaultCodes CD11 Low
Boiler Fault Code CD11
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code CD11 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 displaying a code indicating that the mandatory safety and performance paperwork required after its initial installation or servicing has not been properly registered or finalised. (As reported on Warmflow B-series and Bluebird)
Pick your boiler brand for the CD11 fix
Source
Information for the CD11 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 7 July 2026