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

Typical repair cost for the Baxi Section J fault is £120-250 including labour.

Section J High

Baxi Section J Fault Code

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

Your boiler has detected that it is getting too hot and has automatically switched itself off to prevent any damage or safety issues.

Also written as SECTIONJ — same fault.

The Baxi Section J fault code means: your boiler has detected that it is getting too hot and has automatically switched itself off to prevent any damage or safety issues.. It appears on 2 Baxi models in our database.

Technical description: Overheat thermostat operated or faulty

Typical repair cost £120-250 (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 J fault code

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

Source

Baxi Section J 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