How much does it cost to fix boiler error code d.01?

Typical repair cost for the boiler d.01 fault is £120-200 including labour.

d.01 Low

Boiler Fault Code d.01

Also written as D01 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code d.01 appears across 3 boiler brands and 33 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 running its internal pump longer than expected to move residual heat away from the heating element, which is usually a normal safety feature rather than a breakdown. (As reported on Vaillant Turbomax Plus VUW 242EH)

Pick your boiler brand for the d.01 fix

Glow-worm d.01 8 models Heatline d.01 7 models Vaillant d.01 18 models

Source

Information for the d.01 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 7 July 2026