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F.299 on Viessmann Vitodens 100-W WB1A

Your boiler's internal clock has lost its settings, likely due to a temporary power cut, and simply needs to be reset to the correct date and time.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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.

What the manual says

Manufacturer manual

Real time clock setting incorrect

From this model's manual
Verified against the Viessmann Vitodens 100 W Wb1a installation & service manual, page 87.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Locate the display panel on your boilerAccess the settings menu using the buttons providedUpdate the date and time to the current settings and save

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