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Unsolvable motorised valve problem

Tado technical don't know how to do this so I'm hoping somebody/anybody here can offer some guidance.  


I'm trying to control a normally-closed 5-wire motorised valve (see link below) with a Tado thermostat. I spoke to Tado technical and they said "wire the grey to NO and orange to COM". I did that but as soon a power is applied (blue and brown directly to live and neutral) the valve opens and stays open.  


  Tado support then said "we don't know, ask somebody else".  


Is the valve faulty? Or are the instructions Tado supplied incorrect?  


I looked at the wiring diagram here (https://i.imgur.com/VDYqofj.png) and live to the motor seems to go through the room stat and is switched that way, can i put 240v through the Tado stat and turn it on and off that way?


  • Grey should be wired to live
    Blue to neutral
    Green/yellow to earth
    Brown should go to NO on the 'stat. This should only be energised when heat is called for
    Orange shouldn't go near the 'stat. That's the switched live that turns on the pump and boiler.

    Essentially, thermostat calls for heat and energises brown. This kicks the valve into action and once open, an internal switch energises orange which starts the pump and boiler. This is to prevent the boiler and pump running if the valve fails to open.

    I assume you have a 10 terminal wiring centre somewhere that all the system wiring comes back to?

    I recommend getting an electrician if you're unsure
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