40/06/08 High
Boiler Fault Code 40/06/08
Also written as 400608 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 40/06/08 appears across 1 boiler brand and 2 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is failing to start because it cannot confirm that the internal fan is effectively clearing out used gases before ignition. (As reported on Chaffoteaux Serelia 24 MFFI)
Pick your boiler brand for the 40/06/08 fix
Source
Information for the 40/06/08 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