BoilerFaultCodes D.008 Low
Boiler Fault Code D.008
Also written as D008 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code D.008 appears across 1 boiler brand 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 currently receiving a signal from your wall thermostat telling it to switch on, but the boiler is essentially just reporting that this 'on' status is active. (As reported on Vaillant ecoTEC Plus 836)
Pick your boiler brand for the D.008 fix
Source
Information for the D.008 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 7 July 2026