BoilerFaultCodes Ignition Lockout 1/2 High
Boiler Fault Code Ignition Lockout 1/2
Also written as IGNITIONLOCKOUT12 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code Ignition Lockout 1/2 appears across 1 boiler brand and 1 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler has tried to light several times but failed, so it has locked itself for safety to prevent gas from building up. (As reported on Ideal Logic+ Combi C)
Pick your boiler brand for the Ignition Lockout 1/2 fix
Source
Information for the Ignition Lockout 1/2 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