F.430 Low

Viessmann F.430 Fault Code

Also written as F430 — same fault.

The Viessmann F.430 fault code means: your boiler is having trouble communicating with its smart control connectivity system, which means it cannot link up to external automation devices or remotely adjust your settings.. It appears on 4 Viessmann models in our database.

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description: Connection of automation modules not possible | Communication error, gateway
Typical repair cost £150-300 (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.430 fault code

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

Source

Viessmann F.430 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