Boiler Fault Code d.13

Also written as D13 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026

Fault code d.13 appears across 2 boiler brands and 28 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is currently monitoring or testing the internal pump that moves hot water to your taps, and this specific code is simply a status message confirming it is currently switched off or waiting for a demand. (As reported on Glow-worm Compact)