How much does it cost to fix boiler error code D.50?

Typical repair cost for the boiler D.50 fault is £0-120 including labour.

D.50 Low

Boiler Fault Code D.50

Also written as D50 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code D.50 appears across 2 boiler brands and 35 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning This is a technical status message indicating the boiler is adjusting its fan speed settings and is not usually a hardware fault. (As reported on Vaillant ecoTEC)

Pick your boiler brand for the D.50 fix

Glow-worm D.50 7 models Vaillant D.50 28 models

Source

Information for the D.50 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