How much does it cost to fix Baxi error code Section M?

Typical repair cost for the Baxi Section M fault is £120-£350 including labour.

Section M High

Baxi Section M Fault Code

Q: What does the Baxi Section M fault code mean?

Your boiler has switched itself off because the exhaust gases have become too hot, which is a safety measure to prevent damage to the system.

Also written as SECTIONM — same fault.

The Baxi Section M fault code means: your boiler has switched itself off because the exhaust gases have become too hot, which is a safety measure to prevent damage to the system.. It appears on 2 Baxi models in our database.

Technical description: Flue overheat thermostat may have operated

Typical repair cost £120-£350 (including labour)

Engineer required

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

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Baxi models that show the Section M fault code

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

Source

Baxi Section M fault code information on this page is sourced and cross-checked against the official Baxi service / installation manuals for each affected model.

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