Medium
F.15 on Viessmann Vitodens 200-W B2KF Combi

Your boiler has lost the ability to communicate with your solar heating system or auxiliary heat source, meaning you are relying solely on your main boiler for all hot water and heating.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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.

What the manual says

Manufacturer manual

No solar DHW heating or central heating backup

From this model's manual
Verified against the Viessmann Vitodens 200 W B2kf Combi installation & service manual, page 88.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

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

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