05 High

Boiler Fault Code 05

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code 05 appears across 9 boiler brands and 73 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has lost its connection with the external remote controller, meaning they are unable to talk to each other to manage your heating. (As reported on Vokera Linea 7)

Pick your boiler brand for the 05 fix

Alpha 05 23 models Ariston 05 4 models Chaffoteaux 05 7 models Glow-worm 05 8 models Ideal 05 1 model Remeha 05 1 model Saunier Duval 05 9 models Viessmann 05 7 models Vokera 05 13 models

Source

Information for the 05 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