Boiler Fault Code d.07

Also written as D07 — same fault.

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

Fault code d.07 appears across 2 boiler brands and 21 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 a status code relating to its internal hot water temperature settings, which often occurs when the system is just monitoring its current operation rather than indicating a breakdown. (As reported on Vaillant Thermocompact)