P.01 Medium

Boiler Fault Code P.01

Also written as P01 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code P.01 appears across 1 boiler brand and 29 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has failed while running a specific test used for commissioning or high-power performance checks. (As reported on Vaillant ecoTEC plus)

Pick your boiler brand for the P.01 fix

Source

Information for the P.01 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