E11 Unknown

Vaillant E11 Fault Code

The Vaillant E11 fault code indicates a fault on your boiler. It appears on 2 Vaillant models in our database.

Technical description: Temperature comparison error – Appliance blocked

Engineer required

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

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Vaillant models that show the E11 fault code

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

Source

Vaillant E11 fault code information on this page is sourced and cross-checked against the official Vaillant service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026