Low
S.94 on Viessmann Vitodens 222-F B2TF

Your boiler is working fine but is currently waiting for a Signal from your secondary heating zone controls before it starts warming those specific radiators.

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

No demand; external hook-up, heating circuit 2

From this model's manual
Verified against the Viessmann Vitodens 222 F B2tf 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.

DIY fix possible

Check that the thermostat for your second heating zone is turned up high enough to ask for heatEnsure the batteries in your wireless thermostats are fresh and functioningVerify that any external timers or smart home apps for the second circuit are set to an 'on' period

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Related fault codes

S.91View →S.93View →F.201View →

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