30-80 (L, M, L, L, L, M) Medium

Boiler Fault Code 30-80 (L, M, L, L, L, M)

Also written as 3080LMLLLM — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code 30-80 (L, M, L, L, L, M) 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 struggling to switch between heating your radiators and providing hot water, meaning you may have issues getting a hot shower or heat in your home. (As reported on Chaffoteaux Serelia 24 MFFI)

Pick your boiler brand for the 30-80 (L, M, L, L, L, M) fix

Source

Information for the 30-80 (L, M, L, L, L, M) 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