F.462 Emergency

Viessmann F.462 Fault Code

Also written as F462 — same fault.

The Viessmann F.462 fault code means: your boiler has detected that a safety component responsible for gas control is failing to open properly, preventing the system from igniting.. It appears on 3 Viessmann models in our database.

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

Technical description: LPG safety valve (solenoid valve) at EM-EA1 extension does not open (DIO electronics module).
Typical repair cost £180-350 (including labour)

Engineer required

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

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Viessmann models that show the F.462 fault code

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

Source

Viessmann F.462 fault code information on this page is sourced and cross-checked against the official Viessmann service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026