Section D High

Baxi Section D Fault Code

Also written as SECTIOND — same fault.

The Baxi Section D fault code means: your boiler has detected a failure in one of its internal safety sensors or the fan, meaning it cannot circulate water or vent gases safely and has stopped working.. It appears on 2 Baxi models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: No continuity across flow microswitch, primary temperature sensor faulty, or fan failure
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 D fault code

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

Source

Baxi Section D 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