Tado extension kit wiring ems digital bus and outdoor sensor in worcester bosch greenstar 30i combi

I attempted to wire up a tado extension kit to an ems digital bus by following the app install instructions. When I opened my worcester bosch greenstar 30i combi boiler I found an outdoor temperature sensor wired in using the orange ems connector plug. Can I still wire in the tado extension to ems by purchasing a new connector or I have to disconnect the outdoor temperature sensor.

Thanks for any help.


  • Pete
    Pete ✭✭
    I have a 30cdi with bus wiring.
    I would remove the temperature sensor.
    Tado uses internet weather to determine outside temp so an external sensor is not needed.
  • Tado doesn't support weather compensation so an external sensor would still be required. Whether you can have Tado and an external sensor connected at the same time is another question!
  • gary333
    gary333 ✭✭
    edited March 18

    I am pretty sure you wouldn't be able to have Tado via BUS and weather compensation as there would be a conflict (plus there is usually only one set of ports for both, and you certainly shouldn't be bunging both cables in.

    In theory you should be able to us weather comp and Tado connected by 24RT or 230v switched - so long as the boiler does the computation and not the manufactures controller.

    I don't think Tado uses weather compensation though from what I have seen, or references internet weather. I think it just asks for maximum temp if the differential between current and required temperature is a couple of degrees. As the differential reduces the flow temperature is set to reduce. I personally don't like how it does this as for most who have oversized boilers you are left in a situation where the boiler has no choice but to cycle when the temperature is reduced as the flow water temperature is already higher than the requested.

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