BoilerFaultCodes D.15 Low
Boiler Fault Code D.15
Also written as D15 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code D.15 appears across 1 boiler brand and 18 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 an information code because the pump that moves water around your pipes is spinning at a different speed than expected. (As reported on Vaillant ecoTEC)
Pick your boiler brand for the D.15 fix
Source
Information for the D.15 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