09 High

Saunier Duval 09 Fault Code

The Saunier Duval 09 fault code means: your boiler is struggling to accurately detect the water level inside the system, which is preventing it from safely starting up to provide heating or hot water.. It appears on 6 Saunier Duval 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: Water pressure sensor fault
Typical repair cost £120-220 (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 09 fault code

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

Source

Saunier Duval 09 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