Installing a Nest Thermostat 3rd gen

[Entropy1024]

I'm attempting to install a 3rd gen Nest thermostat in place of my old timer.

Essentially for the Nest system there are two units to install, one is the 'Heat Link' which is rather like the old programmer without any display or buttons. The second unit is the thermostat which has a display and a dual and button for setup/operation etc.

My heating system is a Worcester Greenstar Ri boiler downstairs in the kitchen and a H.W. tank in an upstairs cupboard where there is a junction box of wiring for the heating system.

I have a few main questions.

1. Is MY WIRING SYSTEM a standard S-Plan?
2. Where do you install the Heat Link? I'm guessing it goes where the old programmer currently is, in my case in the kitchen by the boiler. At this location there is a main 240v supply and this is where the live switching to C.H or H.W. is made. However some installs I have seen place it by the H.W. tank.
3. The Thermostat just needs two wires to supply 12v which comes from the Heat Link, simple enough, However to mount the Nest thermostat in the same place as the existing one I can't run any new wires (without huge hassle). As there are already mains running to the existing thermostat, which are no longer required, I was thinking of re-purposing them to supply the 12v. Unfortunately these wires go back to the box by the HW tank upstairs and not where I believe the Heat Link should be installed.

Your help greatly appreciated.

 

[Agile]

We have not seen your system so cannot know what type it is.

You could put the 12v power supply at the cylinder location and send its output down your existing wires.

Since it communicates by wireless to the heat link it does not need any further wires.

Its usual to put the heat link beside your wiring centre to make it easier to connect it.

There are many accredited Nest installers available to install it for you.

Tony

 

[flameport]

It's Y plan.
Nest can go where the programmer was, or at the wiring centre. Just ensure that the wires are all properly labelled before disconnecting them.

 

[Entropy1024]

Cheers Flameport.