How much does it cost to fix boiler error code F31?

Typical repair cost for the boiler F31 fault is £90-180 including labour.

F31 High

Boiler Fault Code F31

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 31 August 2026

Fault code F31 appears across 2 boiler brands and 2 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is having trouble communicating with your thermostat or indoor temperature sensor due to a wiring fault, which may prevent your heating from turning on correctly. (As reported on Viessmann Vitodens 025-W)

Pick your boiler brand for the F31 fix

Ferroli F31 1 model Viessmann F31 1 model

Source

Information for the F31 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