Nest Central Heating and UFH

[TB13]

Hello all, new to the forum but had a good look to see if I could find answers to my questions but couldn’t see anything quite the same- hoping someone can help.

I have a system boiler (converted from a combi) with two heating zones, upstairs and downstairs, controlled by separate Nests. The hot water cylinder is controlled by a regular time clock (Homexpert by Honeywell).

We have just had an extension built which has wet underfloor heating and we want to run this using a third Nest but not sure how.

Can anyone offer any advice as we’d like to run the 3 zones on their own Nests and I haven’t been able to see how this is possible so far! Thanks, TB

 

[muggles]

You add the third in much the same way as the second was added. Your new wet UFH system should have its own zone valve, probably by your boiler, and that will be wired into the wiring centre. How is the UFH controlled at the moment, or did the installers not provide any control?

 

[TB13]

You add the third in much the same way as the second was added. Your new wet UFH system should have its own zone valve, probably by your boiler, and that will be wired into the wiring centre. How is the UFH controlled at the moment, or did the installers not provide any control?

Thanks for your reply. It’s still all new and the main contractor hasn’t used Nest before so it’s a bit confused.

The UFH manifold is piped from the Boiler and is at the other side of the room, there is what looks like a zone valve on the pipes at the manifold end, as well as a pump.

I think what’s causing the confusion is how to get the heat link connected as a 3rd “zone” rather than being on the “downstairs” zone.

I hope this makes sense.

 

[muggles]

I hope this makes sense.

Not really. It's just a switch which any competent heating installer can fit. Heat link L and 2 terminals go to the grey wire on the zone valve, N to blue, and 3 to brown. If they've been sensible enough to put wires in for a wired thermostat, you connect those wires to T1 & T2 in the heat link, and to the Nest backplate at the other end. Couldn't be simpler

 

[muggles]

I once did a full ground floor of UFH with five Nests...

 

[TB13]

Thanks for your help- we seem to have sorted it now, looks like the original switch that was put in to control the UFH had a faulty fuse (oops), now replaced and all seems ok!

 

[TB13]

I once did a full ground floor of UFH with five Nests...

View attachment 162832

Ps. Neat work!