18 High

Saunier Duval 18 Fault Code

The Saunier Duval 18 fault code means: your boiler's electronic display is experiencing a communication error, meaning the main controls are currently unable to operate the heating and hot water correctly.. It appears on 4 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: Local user interface fault
Typical repair cost £150-300 (including labour)

Engineer required

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

Find a Gas Safe engineer

Search the official register for a qualified engineer in your area.

Gas Safe Register →

Saunier Duval models that show the 18 fault code

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

Source

Saunier Duval 18 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