Boiler Fault Code d.36

Also written as D36 — same fault.

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

Fault code d.36 appears across 3 boiler brands and 32 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 detect or regulate the flow of water needed to provide your hot taps, often because the system is sensing an issue with the water moving through it. (As reported on Glow-worm MicraCom)