F.547 Medium

Viessmann F.547 Fault Code

Also written as F547 — same fault.

The Viessmann F.547 fault code means: your boiler has detected that the valve controlling the water temperature to your radiators has closed, which means your heating may not get as warm as you have set it.. It appears on 4 Viessmann models in our database.

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description: Mixer closes. Heating circuit pump is operational.
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.547 fault code

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

Source

Viessmann F.547 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