04/05/06/08 High

Boiler Fault Code 04/05/06/08

Also written as 04050608 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code 04/05/06/08 appears across 2 boiler brands and 7 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is struggling to move hot water around the system effectively, which is causing it to overheat and shut itself down as a safety precaution. (As reported on Chaffoteaux Serelia 24 MFFI)

Pick your boiler brand for the 04/05/06/08 fix

Chaffoteaux 04/05/06/08 2 models Viessmann 04/05/06/08 5 models

Source

Information for the 04/05/06/08 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