Vaillant P2 Fault Code
The Vaillant P2 fault code means: your boiler is failing to start up because it cannot reliably ignite the gas flame required to provide heating or hot water.. It appears on 1 Vaillant model in our database.
Technical description: Ignition rate
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Vaillant models that show the P2 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vaillant P2 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 27 April 2026