A 37 High

Chaffoteaux A 37 Fault Code

Also written as A37 — same fault.

The Chaffoteaux A 37 fault code means: your boiler's main control computer is experiencing an internal error and cannot operate safely, meaning your heating and hot water will not work until it is reset or repaired.. It appears on 3 Chaffoteaux 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: CPU fault
Typical repair cost £250-450 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Chaffoteaux models that show the A 37 fault code

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

Source

Chaffoteaux A 37 fault code information on this page is sourced and cross-checked against the official Chaffoteaux service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026