BoilerFaultCodesVaillant F00 Fault Code
The Vaillant F00 fault code indicates a fault on your boiler. It appears on 2 Vaillant models in our database.
Technical description: Interruption of flow NTC (NTC1)
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 F00 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vaillant F00 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