Boiler Fault Code d.19

Also written as D19 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026

Fault code d.19 appears across 2 boiler brands and 20 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning This code is simply an information status display showing how your boiler's internal water pump is currently being told to operate, rather than an error or a fault with your heating system. (As reported on Vaillant ecoTEC Plus 615)