How much does it cost to fix Saunier Duval error code 1 9?

Typical repair cost for the Saunier Duval 1 9 fault is £120-250 including labour.

1 9 High

Saunier Duval 1 9 Fault Code

Q: What does the Saunier Duval 1 9 fault code mean?

Your boiler has shut down because it thinks the water returning to the system is dangerously hot, which could indicate a flow blockage or a faulty sensor.

Also written as 19 — same fault.

The Saunier Duval 1 9 fault code means: your boiler has shut down because it thinks the water returning to the system is dangerously hot, which could indicate a flow blockage or a faulty sensor.. It appears on 2 Saunier Duval models in our database.

Technical description: The heating return thermistor is detecting an excessive temperature.

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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Saunier Duval models that show the 1 9 fault code

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

Source

Saunier Duval 1 9 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