How much does it cost to fix Saunier Duval error code 37.?

Typical repair cost for the Saunier Duval 37. fault is £150-250 including labour.

37. High

Saunier Duval 37. Fault Code

Q: What does the Saunier Duval 37. fault code mean?

Your boiler is struggling to accurately measure the temperature of the water circulating back from your radiators, causing it to stop working as a safety precaution.

Also written as 37 — same fault.

The Saunier Duval 37. fault code means: your boiler is struggling to accurately measure the temperature of the water circulating back from your radiators, causing it to stop working as a safety precaution.. It appears on 4 Saunier Duval models in our database.

Technical description: The heating return thermistor is too resistant.

Typical repair cost £150-250 (including labour)

Engineer required

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

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Saunier Duval models that show the 37. fault code

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

Source

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

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026