How much does it cost to fix boiler error code E4?

Typical repair cost for the boiler E4 fault is £160-£320 including labour.

E4 High

Boiler Fault Code E4

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code E4 appears across 5 boiler brands and 46 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has detected a problem with how it controls the gas flow, meaning it cannot safely regulate the flame and has shut down as a precaution. (As reported on Worcester Bosch WR325 RSF)

Pick your boiler brand for the E4 fix

Baxi E4 24 models Ideal E4 1 model Remeha E4 11 models Viessmann E4 8 models Worcester Bosch E4 2 models

Source

Information for the E4 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