Nest learning thermostat

[Chris]

Hi,
I went to a job yesterday to install 2 x nest smart thermostats on an S plan system with 2 heating zones.

when I took the cover off the wiring centre the cables from the central heating zones, cylinder stat and hot water were pre made plugs that clip into the circuit board as opposed to connector blocks.

anyone came across this before and if so how did you resolve?

I’m currently thinking if I disconnect the two zones and hot water at the end points and connect them with the nest heat link in a separate enclosure, connect them with the heat link cables and then wire back to each point It will resolve the problem? If my words even make sense there..

Any help appreciated, wiring centre picture here

 

[Pete999]

Hi,
I went to a job yesterday to install 2 x nest smart thermostats on an S plan system with 2 heating zones.

when I took the cover off the wiring centre the cables from the central heating zones, cylinder stat and hot water were pre made plugs that clip into the circuit board as opposed to connector blocks.

anyone came across this before and if so how did you resolve?

I’m currently thinking if I disconnect the two zones and hot water at the end points and connect them with the nest heat link in a separate enclosure, connect them with the heat link cables and then wire back to each point It will resolve the problem? If my words even make sense there..

Any help appreciated, wiring centre picture here

Those CPCs are a bit of a mess.

 

[EricMark]

Seem to remember coming across that some years ago and found pumps and valves were 24 volt. Think it was a now discontinued Honeywell system.

 

[Dobes_88]

A lot of the pre plumbed unvented cylinders come with a similar wiring centre stuck to it, I'm actually at a job tomorrow I've done recently with the same set up - if I remember will take a picture of the wiring centre. I didn't need to do a separate enclosure, just literally a 4/5 core from the programmer part on the wiring centre to heat link.

 

[davesparks]

I’m currently thinking if I disconnect the two zones and hot water at the end points and connect them with the nest heat link in a separate enclosure, connect them with the heat link cables and then wire back to each point It will resolve the problem? If my words even make sense there..

You don't need to disconnect the valves to connect the nest.
The terminals you need to connect to are screw terminals. The nest replaces the programmer and room thermostats, the three valves and cylinder stat can stay exactly as they are.
Just check whether that box is LV or ELV before you connect anything.