Tado on Volt Free S Plan system

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I have just picked up the Tado V3 Kit (Wireless stat, plus hot water controller) in prime day deals, though before I go crazy I have some questions.

The installation manual cannot help me as says "not compatible" as I have the Scottish power connect, HOWEVER, The Scottish power connect is no different to many other controllers.

Below is by Boilers wiring diagram that is currently how I have it set up. (Fusion Comet, 24kw, 3 Phase System on S Plan)


My Scottish power controller is wire for this system.

3 is my HW Call & 4 is my heating call. I can see in the extension kit, I could wire these in to the relevant connections. Though on the tado, this has a connection back to the boil (live/neutral) where as as you can see from above, 14/15 are my volt free signals to the boiler.

I am fully confident in any wiring mods (electrician but been out of the game for 10 years).

I confident the Tado can do what I am saying but I don't want to go blowing anything up :D

Any pointers would be great.

Thank you.