Section L High

Boiler Fault Code Section L

Also written as SECTIONL — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code Section L appears across 2 boiler brands 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 is not receiving a signal to turn on, which is likely due to the timer settings or the thermostat connections not communicating correctly. (As reported on Alpha 240XE)

Pick your boiler brand for the Section L fix

Source

Information for the Section L 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 27 April 2026