P04 Low

Boiler Fault Code P04

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code P04 appears across 2 boiler brands and 3 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is temporarily pausing because the water in the tank has become too hot and now needs to cool down slightly before the system can restart automatically. (As reported on Ferroli Leb TS)

Pick your boiler brand for the P04 fix

Alpha P04 2 models Ferroli P04 1 model

Source

Information for the P04 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