BoilerFaultCodes P x.x Low
Boiler Fault Code P x.x
Also written as PXX — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code P x.x appears across 1 boiler brand 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 providing a live reading of the current water pressure in your heating system, which is a standard status display rather than a fault. (As reported on Atag Q 25S)
Pick your boiler brand for the P x.x fix
Source
Information for the P x.x 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