High
F.377 on Viessmann Vitodens 222-F B2TH-32

Your boiler has run into a problem setting up how it burns gas safely, so it has stopped as a precaution and needs a qualified engineer to check it.

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

Automatic calibration of the combustion controller fails. Check gap between ionisation electrode and burner gauze assembly. Check flue system. Remove flue gas recirculation if required. Reset device.

From this model's manual
Verified against the Viessmann/Viessmann Vitodens 222 F B2th 6219766 installation & service manual.
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.22View →F.28View →F.29View →

All 12 fault codes on the Vitodens 222-F B2TH-32

Seeing a different code? Every code this model can display, in one place.

A.11F.59F.62F.346F.357F.359F.369F.373F.380F.416F.457

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