How much does it cost to fix boiler error code F40?

Typical repair cost for the boiler F40 fault is £150-300 including labour.

F40 High

Boiler Fault Code F40

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code F40 appears across 3 boiler brands and 16 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler's computer has lost its internal settings, meaning it no longer knows how to operate correctly and has shut itself down as a precaution. (As reported on Ferroli Bluehelix Tech RRT 24C)

Pick your boiler brand for the F40 fix

ECA F40 4 models Ferroli F40 10 models Johnson Starley F40 2 models

Source

Information for the F40 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