Low
dA on Viessmann Vitodens 343-F WS4A

Your boiler has lost the signal from its room thermostat sensor, so it is heating your home using only the outside temperature, which means it may not hold the room at exactly the temperature you set, but it should still keep heating and hot water working.

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

Control mode without room influence - Room temperature sensor, heating circuit A1 shorted out

From this model's manual
Verified against the Viessmann/Viessmann Vitodens 343 F Ws4a 5592883 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 fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

dFView →F22View →

All 59 fault codes on the Vitodens 343-F WS4A

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

0F9A9b9C9F10182028303840485058929394A6A7b0b1b4b5b7b8bAbCbdbEbFC2CdCECFdbdddEE4E5E8E9EAEbECEdF0F1F2F3F4F8F9FAFCFdFEFF

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