How much does it cost to fix Saunier Duval error code 23?

Typical repair cost for the Saunier Duval 23 fault is £150-350 including labour.

23 High

Saunier Duval 23 Fault Code

Q: What does the Saunier Duval 23 fault code mean?

Your boiler is struggling to detect water properly circulating through its system, which means it will stop producing heat and hot water as a safety precaution.

The Saunier Duval 23 fault code means: your boiler is struggling to detect water properly circulating through its system, which means it will stop producing heat and hot water as a safety precaution.. It appears on 3 Saunier Duval models in our database.

Technical description: FLOW RATE FAULT / CALL AFTERSALES

Typical repair cost £150-350 (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 23 fault code

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

Source

Saunier Duval 23 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