How much does it cost to fix boiler error code P11?

Typical repair cost for the boiler P11 fault is £120-200 including labour.

P11 Medium

Boiler Fault Code P11

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code P11 appears across 3 boiler brands and 4 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 status alert indicating that an internal moisture protection setting has been activated to protect sensitive electrical components. (As reported on Alpha Pro Tec Plus)

Pick your boiler brand for the P11 fix

Alpha P11 2 models Ferroli P11 1 model Vaillant P11 1 model

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 7 July 2026