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

Typical repair cost for the Baxi Section I fault is £120-220 including labour.

Section I High

Baxi Section I Fault Code

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

Your boiler is failing to detect that it has successfully lit the flame, so it is turning itself off as a safety precaution.

Also written as SECTIONI — same fault.

The Baxi Section I fault code means: your boiler is failing to detect that it has successfully lit the flame, so it is turning itself off as a safety precaution.. It appears on 2 Baxi models in our database.

Technical description: Flame sensing fault: flame sensing electrode/lead connections or electrode position

Typical repair cost £120-220 (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 I fault code

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

Source

Baxi Section I 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