BoilerFaultCodes 5 P 1 High
Boiler Fault Code 5 P 1
Also written as 5P1 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 5 P 1 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 has failed to start up on its first try and may need a quick manual reset to get it running again. (As reported on Ariston HS Premium)
Pick your boiler brand for the 5 P 1 fix
Source
Information for the 5 P 1 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