How much does it cost to fix boiler error code F.15?

Typical repair cost for the boiler F.15 fault is £150-300 including labour.

F.15 Medium

Boiler Fault Code F.15

Also written as F15 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code F.15 appears across 4 boiler brands and 9 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has lost the ability to communicate with your solar heating system or auxiliary heat source, meaning you are relying solely on your main boiler for all hot water and heating. (As reported on Viessmann Vitodens 200-W B2KF Combi)

Pick your boiler brand for the F.15 fix

Glow-worm F.15 1 model Ideal F.15 2 models Johnson Starley F.15 2 models Viessmann F.15 4 models

Source

Information for the F.15 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