How much does it cost to fix boiler error code F74?

Typical repair cost for the boiler F74 fault is £120-190 including labour.

F74 High

Boiler Fault Code F74

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 31 August 2026

Fault code F74 appears across 2 boiler brands and 10 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 measuring how much water is inside the system, which is causing it to stop running for safety. (As reported on Glow-worm Ultracom 35 Store)

Pick your boiler brand for the F74 fix

Glow-worm F74 8 models Heatline F74 2 models

Source

Information for the F74 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