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

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

Also written as 3080MMLMMM — same fault.

The Chaffoteaux 30-80 (M, M, L, M, M, M) fault code means: your boiler is mistakenly detecting a flame when it shouldn't be, which is a safety lockout preventing it from firing up.. It appears on 2 Chaffoteaux models in our database.

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

Technical description: Fire detection without burner working
Typical repair cost £150-250 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Chaffoteaux models that show the 30-80 (M, M, L, M, M, M) fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Chaffoteaux 30-80 (M, M, L, M, M, M) fault code information on this page is sourced and cross-checked against the official Chaffoteaux service / installation manuals for each affected model.

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