BoilerFaultCodes D.043 Low
Boiler Fault Code D.043
Also written as D043 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code D.043 appears across 1 boiler brand and 3 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is displaying a status code related to its internal heating settings rather than a breakdown, meaning it is simply calculating the required water temperature based on your current configuration. (As reported on Vaillant ecoTEC Plus 832)
Pick your boiler brand for the D.043 fix
Source
Information for the D.043 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