BoilerFaultCodesSaunier Duval F11 Fault Code
The Saunier Duval F11 fault code means: your boiler is having trouble communicating with its control panel, which means it isn't receiving the instructions it needs to provide heating or hot water.. It appears on 6 Saunier Duval models in our database.
Technical description: User interface connection fault. Check wiring between mainboard and user interface
What causes the Saunier Duval F11 fault?
This fault occurs when the data link between the boiler's internal computer and the front display panel is broken, preventing the two parts from 'talking' to each other. It is usually caused by a loose plug, a damaged wire, or a failing electronic chip on one of the circuit boards. Because the boiler cannot confirm its settings or safety parameters, it stops running as a precaution.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Saunier Duval models that show the F11 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Saunier Duval F11 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