High
F.517 on Viessmann Vitodens 222-F B2TF

Your boiler is having trouble communicating with its external thermostat or remote control, meaning it cannot receive the correct instructions to heat your home.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

Lead break PlusBus / incorrect address / remote control faulty

From this model's manual
Verified against the Viessmann Vitodens 222 F B2tf installation & service manual, page 104.
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 is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

F.518View →F.92View →F.108View →

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