Nest 3rd Gen Installation onto Alpha 28c

12 Jan 2017
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United Kingdom
Hi All,

I have recently taken delivery of a nest 3rd generation and fairly confident in installing it but for my own clarity can the following be confirmed for me.

Currently have an alpha 28c boiler with the alpha receiver plumbed into it as below (attached)

Now the wiring the diagram matches the same as within the manual as below

My thoughts are it's a simple case of removing the Blue (neutral) and Brown (Live) and fixing them into the Live and Neutral on the heat Link, but the red wires are what throwing me out a tad! I have two wires as per the same receiver alpha image (attached) but unsure which to feed into my heat link do i place the wire from 3 into slot 2 (which is connected to live via the link over 1 and 2) on heat link and wire from 4 into slot 3 on heat link?

I think i have it right but just need clarification if someone could be of help?



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Looking at your photo you might already have the live loop in that connector block. can you show us a picture of that in more detail. Also can you upload an image of the nest link ports and what connections they are so we can be sure we give you the right info (pins 1,2,3 should be NO,C,NC but maybe in reverse)

But it does seem like you said take the L/N off and wire into the nest link. and then take the red wires and wire into NO & C on the nest link.

Apologies at work so don't have a closer image of the receiver to hand
Above is the Nest Heat Link diagram, i think I've got confused because of how the diagram looks and how my boiler diagram is!
I believe that the link into my current boiler receiver, is as follows to match the nest system

L pin 1 (reciever) to L on nest
N pin 2 to N on nest
Pin 3 to Pin 2 on Nest this has the live link in the connector block so matches the connection on the photo above but just in a round about way
Pin 4 to Pin 3 on Nest this connects directly to the boiler

Below is the Nest Heat Link Connectors



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Yeah that all looks good, would be happy to just double check that connector block when your able to get a photo. Also can you confirm that there's no loop from L, N etc.. on the nest to any other connections on the nest.
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Thanks for all the help omega015, i've managed to get it all installed successfully :)

Did have a moment when all the lights in the house flickered just after fitting and though o no what's gone wrong! but all the area had the problem so sphincter was happy haha!!
Hello, I have almost the same wiring in my boiler (Alpha 24X) and want to connect my new nest thermostat. Could you please explain in detail how you did that? Did you remove the receiver? Also did you connect nest to the boiler (pins L-N-3-4 on X3 shown in the picture)? what about the other connector block (pins L-N-1-2) and the link between 1-2?


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