Installing a Nest Thermostat

user060916

I'm looking to install a Nest Thermostat.

My Current Programmer is wired below:

It is labeled (from L to R) N L 1 2 3 4

I'm a bit confused as to how this maps to the Google Nest Thermostat and the purpose of the jumper between L and 1 in my current set up. I'd appreciate any advice.

tikka16751

The purpose of the jumper in your existing set up is to give you mains in on your switch output.

If that jumper wasn’t there it would be a volt free switching.

user060916

https://www.boards.ie/discussion/comment/121447669#Comment_121447669

Okay, not going to lie, that went a bit over my head. Would you be able to tell me where each wire should go in the nest thermostat?

I'd like to do this myself if possible (with the mains off) but obviously don't want to take risks,

tikka16751

https://www.boards.ie/discussion/comment/121447675#Comment_121447675

What is your current setup as in zones?

user302243

Just the one zone

ongarite

Your photo appears to show 2 zones.

The black wire on the right? Is it for hot water timer?

Can you take photo of your original programmer?

Edit:

It maybe 1 zone with light brown as common with bridged live connection & then black for NO/call for heat.

tikka16751

https://www.boards.ie/discussion/comment/121447699#Comment_121447699

Confirm this first in case the nest is already switching mains but it looks like it isn’t so you would put a jumper from L to 2 and output which is your black wire to 3.

ongarite

blue to N, brown to L

Light brown to 2 and black to 3. You may need to use that red cable to bridge L and 2 but try it without it first.

kirk.

https://www.boards.ie/discussion/comment/121447723#Comment_121447723

It's 1 Zone . Won't work without link

(There's a perm feed continuing to boiler or a frost stat connection probably)

user060916

https://www.boards.ie/discussion/comment/121447715#Comment_121447715

You could be right - still learning the system. When the gas boiler is on the hot water tank is heated - though it's not on it's own schedule, it's central heating and hot water together.

It is a CTC EXIPROG 1 (EP1) 1 Channel Programmer currently.