BoilerFaultCodes P11 Low
Boiler Fault Code P11
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code P11 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 performing a factory calibration check to ensure the gas and air balance is set correctly for your home's fuel supply. (As reported on Vaillant Thermocompact)
Pick your boiler brand for the P11 fix
Source
Information for the P11 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