Fitting A Nest Heat Link

[Mark Phillips]

Hi I'm a newbee, looking to install a Nest thermostat in place of the current manual room thermostat and was after a little information and clarification before I start.

I currently have a wall mounted mechanical Horstmann HRT3 thermostat which has x2 wires (which measure 12V on a meter) 1x Red wire in connector 1 and 1x Blue wire in conector 3. These both back to a jct box and change to 1x Brown and 1x Blue cables and go back to TA1 on my Ariston Combi Evo boiler which has a sticker no 240v on the connector.

With regards to Nest installation, my understanding is that I connect a 240v supply to the L + N connections on the nest Heatlink for power, and the x2 12v cables on TA1 from my boiler (Currently going my thermostst) , go to conections 2 + 3 on the Heatlink.. Then my new Nest Thermostat connects to T1 + T2 on the Heatlink..

I have attached a couple of photos of the current connections on my old thermostst, jct Box, and Boiler connections along with a wiring diagram for the Nest Heat Link.

Thanks in Advance.. Regards Mark

 

[slippyr4]

You are correct. The "Low voltage / dry contact combi boiler" wiring is what you want.

 

[Mark Phillips]

Much appreciated for the prompt reply. With regards to the Brown/Blue cables on boiler TA1 that currently go to the thermostat, do you know which would go to con 2 and con 3 on the heat link? Thanks

 

[hertsboilers]

Much appreciated for the prompt reply. With regards to the Brown/Blue cables on boiler TA1 that currently go to the thermostat, do you know which would go to con 2 and con 3 on the heat link? Thanks

It doesn't matter, as it is a switch.

 

[Mark Phillips]

Ok, thought as there was a 12v reading perhaps it mattered.. Many Thanks for the advise, appreciate the prompt feedback.. Regards Mark

 

[kingchristo]

im looking installing one of these thermostats too. I have the same boiler and old setup. did you take the power from the boiler or somewhere else thanks

 

[ianmcd]

you can take the 240v supply from the boiler or the outlet of the fused spur whatever is easiest,