BoilerFaultCodes D.070 High
Boiler Fault Code D.070
Also written as D070 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code D.070 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 struggling to switch between heating your radiators and heating your hot water, which may lead to your home being cold or your taps running with lukewarm water. (As reported on Vaillant ecoTEC Pro 28)
Pick your boiler brand for the D.070 fix
Source
Information for the D.070 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