Boiler Fault Code L A (flashing)

Also written as LAFLASHING — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026

Fault code L A (flashing) appears across 1 boiler brand and 2 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has switched itself off because it has detected an unsafe build-up of heat, requiring a professional to check for internal circulation or sensor issues. (As reported on Ideal Icos)