Boiler Fault Code -ll-

Also written as LL — same fault.

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

Fault code -ll- 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 is performing a routine internal safety check to ensure internal water levels are correct and will return to normal operation automatically within 15 minutes. (As reported on Worcester Bosch R30 HE Plus)