BoilerFaultCodes F8 or L8 High
Boiler Fault Code F8 or L8
Also written as F8ORL8 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code F8 or L8 appears across 1 boiler brand and 3 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 a communication error with its internal computer or a wiring fault near the gas supply, meaning it has safely switched off to prevent potential issues. (As reported on Ideal Atlantic Combi)
Pick your boiler brand for the F8 or L8 fix
Source
Information for the F8 or L8 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