Brand new boiler install with nest

7 Feb 2018
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United Kingdom
Good evening all and apologies for what i can imagine is the millionth nest query but after trawling through the forum i couldnt find what i need.i have a brand new baxi duo tec has no manual timer, programmer or thermostat so i have bought a 3rd gen Nest thermostat. I am confused as to what wires need to go where and what wires need to be disconnected to connect the heatlink. I am having the thermostat plugged in via a normal socket. Any help will be greatly received.
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First of all, My qualifications are electrical, so I'm not au fait with the intricacies of your particular boiler. So, if you find that you have to open up the 'room sealed' part of the boiler to access the wiring terminals, this is not a DIY project and should only be done by a Gas Safe engineer who can then carry out the necessary safety checks afterwards.

And you are right, it has been covered before there's an example here. But I've copied the pertinent points from the post in the link for you below:

1) The Nest Heatlink Live, Neutral & Earth will be wired into the Live, Neutral and Earth terminals labelled 3A supply at the Baxi.
2) In the same photo, there is a yellow link wire between terminals 1 & 2. remove the link.
3) Connect terminal 2 of the Baxi (Live out) to the Heatlink terminal 2 (Common)
4) Connect terminal 1 of the Baxi (Live in) to the Heatlink terminal 3 (Call for Heat)

The Heatlink and Boiler should be supplied from the same 230V supply source.

If you want to power the Nest thermostat from the Heatlink then connect T1 & T2 at the Heatlink to the corresponding terminals at the thermostat, or alternatively use the separate plug in power supply for the thermostat.
Last edited:
Hi stem. I did indeed eventually come across your reply on another thread. I have now managed to successfully install nest to my boiler.thank you
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