BoilerFaultCodes d.02 Low
Boiler Fault Code d.02
Also written as D02 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code d.02 appears across 1 boiler brand and 22 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler has reached its target temperature and is taking a short rest to prevent it from turning on and off too frequently, which protects the internal components. (As reported on Vaillant ecoFIT pure)
Pick your boiler brand for the d.02 fix
Source
Information for the d.02 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