A.02 .37 High

Baxi A.02 .37 Fault Code

Also written as A0237 — same fault.

The Baxi A.02 .37 fault code means: your boiler has lost its connection to an essential internal sensor, meaning it cannot safely monitor its own operation and has shut down to protect itself.. It appears on 5 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: Passive functional device disconnected
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 A.02 .37 fault code

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

Source

Baxi A.02 .37 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 7 July 2026