Viessman,Tado wired Thermostat.

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Good afternoon, I have got a Viesmann 100-W system boiler with a Heatrae Sadia Megaflo.

I have the Vitotrol 100 UTDB-RF2 wireless thermostat/programmer.

I have the wired Tado smart thermostat in and connected to internet but have been informed I need the extension kit also.

I have also been told that this will not control my hot water, do I need to maintain the Vitotrol wireless programer to do the hot water? Not sure how these would work together?

Thanks in advance, I seem to have a few issues to resolve.

Paul

Comments

  • GrayDav4276
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    @PHeath217
    I have a Viessmann 050-W combi boiler.
    I "retired" the Vitotrol 100 UTDB-RF2 wireless thermostat/programmer, and fitted the tado° Extension Kit. This allows control of the CH and also the HW.
    My system is made up of the following.
    Extension Kit
    Internet Bridge
    Wireless Thermostat
    Wireless Temperature Sensor
    10 Smart Radiator Thermostats
  • PHeath217
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    Ah ok thanks for response, mine is a system boiler which Tado say their system cannot run the hot water because of the boilers internal motorized valve.

  • GrilledCheese2
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    @PHeath217 most boilers have a thermostatic switch for the hot water cylinder to control when the boiler is on/off. Your Viessmann boiler is a bit different owing to it being a four pipe system with an internal valve. There's a temperature sensor for the cylinder that uses a low voltage signal to represent the measured temperature. Unfortunately you cannot switch this signal on and off to control the cylinder - the boiler simply reads the sensor value all the time to determine if the cylinder needs heating.

    I think this is why Tado have told you that you need to retain the vitotrol programmer to manage the HW generation.

  • PHeath217
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    @GrilledCheese2 many thanks.

    I see the need for that now but cannot understand why the the Tado will not do the heating, the thermostat and extension kit are connected and the app on the phone connects to the smart thermostat but nothing happens at the boiler. Also, what setting do I leave the Vitotrol programmer on to operate the DHW only?

    I did wonder whether or not it would be easier to just go Vitoconnect?

    Many thanks

    Paul.

  • GrilledCheese2
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    I think you need to get an answer from Tado whether they are supporting the digital bus interface or the traditional relay interface. The wiring and device configuration are different for each. If you get it wrong the app will still appear to work, but the boiler will not operate.