Fd Low

Boiler Fault Code Fd

Also written as FD — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code Fd appears across 5 boiler brands and 58 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is simply confused because the reset button was held down for too long or pressed when it wasn't needed. (As reported on Worcester Bosch Greenstar 25HE)

Pick your boiler brand for the Fd fix

British Gas Fd 1 model Ferroli Fd 1 model Ideal Fd 4 models Viessmann Fd 15 models Worcester Bosch Fd 37 models

Source

Information for the Fd 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