BoilerFaultCodes D.001 Low
Boiler Fault Code D.001
Also written as D001 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code D.001 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 simply running its internal water pump for a bit longer than usual to ensure all the leftover heat is safely moved away from the burner after the heating has switched off. (As reported on Vaillant ecoTEC Plus 832)
Pick your boiler brand for the D.001 fix
Source
Information for the D.001 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