D Medium

Baxi D Fault Code

The Baxi D fault code means: your boiler has temporarily stopped working because it cannot accurately read its internal temperature.. It appears on 5 Baxi models in our database.

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description: Temperature sensor faulty
Typical repair cost £90-180 (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 D fault code

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

Source

Baxi 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 31 August 2026