How much does it cost to fix boiler error code 30-80 (L, L, M, L, M, M)?

Typical repair cost for the boiler 30-80 (L, L, M, L, M, M) fault is £120-200 including labour.

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

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

Also written as 3080LLMLMM — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code 30-80 (L, L, 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's temperature sensor is disconnected or faulty, meaning it cannot accurately measure how hot the water is to safely heat your radiators. (As reported on Chaffoteaux Serelia 24 MFFI)

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

Chaffoteaux 30-80 (L, L, M, L, M, M) 2 models

Source

Information for the 30-80 (L, L, 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