How much does it cost to fix boiler error code P4?

Typical repair cost for the boiler P4 fault is £0-120 including labour.

P4 Low

Boiler Fault Code P4

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code P4 appears across 2 boiler brands and 5 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is undergoing a startup sequence or a temporary software update and needs time to finish its internal checks. (As reported on Worcester Bosch R30 HE Plus)

Pick your boiler brand for the P4 fix

Ideal P4 1 model Worcester Bosch P4 4 models

Source

Information for the P4 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