BoilerFaultCodes D.022 Low
Boiler Fault Code D.022
Also written as D022 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code D.022 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 correctly registering that you have turned on a hot water tap and is beginning the process of heating the water for you. (As reported on Vaillant ecoTEC Pro 30)
Pick your boiler brand for the D.022 fix
Source
Information for the D.022 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