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

Typical repair cost for the boiler d.50 fault is £90-180 including labour.

d.50 Low

Boiler Fault Code d.50

Also written as D50 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 31 August 2026

Fault code d.50 appears across 2 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 displaying an internal message regarding how slowly the fan is spinning, which usually means the system is attempting to calibrate itself but may need a professional adjustment. (As reported on Vaillant ecoFIT Pure 425)

Pick your boiler brand for the d.50 fix

Glow-worm d.50 7 models Vaillant d.50 25 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 31 August 2026