How much does it cost to fix boiler error code F04?

Typical repair cost for the boiler F04 fault is £90-160 including labour.

F04 High

Boiler Fault Code F04

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code F04 appears across 3 boiler brands and 5 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has detected an issue with the sensor that monitors the temperature of the water leaving the unit, which means it cannot heat your home or water safely. (As reported on Ideal Logic Max System)

Pick your boiler brand for the F04 fix

Ferroli F04 3 models Ideal F04 1 model Viessmann F04 1 model

Source

Information for the F04 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