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

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

Also written as 3080LMMLMM — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code 30-80 (L, M, M, L, M, 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 has lost the ability to detect the temperature of the water used for your taps and shower, so it has stopped providing hot water to ensure safety. (As reported on Chaffoteaux Serelia 24 MFFI)

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

Source

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