04 High

Boiler Fault Code 04

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code 04 appears across 8 boiler brands and 68 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 ignite or stay lit after several attempts and requires a manual reset and investigation by a professional. (As reported on Vokera Linea HE)

Pick your boiler brand for the 04 fix

Alpha 04 22 models Glow-worm 04 6 models Ideal 04 1 model Ravenheat 04 8 models Remeha 04 3 models Saunier Duval 04 8 models Viessmann 04 7 models Vokera 04 13 models

Source

Information for the 04 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