Another Nest E question...

[Jcooper29]

Hi all,
I’m new here and have a question regarding the Nest E installation. I’ve seen all the posts about this that already exist, but most are regarding the 3rd gen, which is different.

I currently have a 28i junior combo boiler and bdr91 wireless thermostat. I have a nest e on its way and wanted to check that what I am doing will be correct.

I just need to insulate the current n and l and use the a and b for the nest? And would it then be safe for the low voltage requirement?

Thanks in advance!

 

[jackthom]

If the heatlink is going where the bdr91 is located, the Live and Neutral will be needed to power the heatlink and the other two wires will go to terminals 2 and 3 in the heatlink.

Terminals 2&3 operate simply as a switch and won’t damage the boiler by connecting any high voltages to it.

 

[Jcooper29]

Thanks for this information, my issue is that I am getting the nest e, which is slightly different. It is battery powered and so only requires two cables. Do I just leave the N and L cables as they are but with tape around them?

 

[jackthom]

Apologies I haven’t played with the e heatlink and forgot it was battery powered. You may not have enough room to do much with the live and neutral wire apart from snipping off the exposed part of the wires and, while ensuring they are not in contact with each other, tape them up.

Can you find where this power cable comes from? It should be fed from the spur supplying the boiler in which case you might be able to completely disconnect it at that point.

 

[Jcooper29]

Ok thanks, yes it comes from the fused spur next to the bdr91. It’s all behind plasterboard so I think I’ll just wrap up the ends and poke it back into the boxed out wall. So I am right in saying the A/B and No/C connections won’t damage the nest E from high voltage?

 

[muggles]

I suspect you'll need to keep the two Lives and two Neutrals connected together, or nothing will work.

 

[ianmcd]

As @muggles says , the two lives connected together in 1 terminal block, and the two neutrals connected together in a different terminal block, insulate then pop in behind the wall then A&B to NO and Com, either way round it doesnt matter, the nest E can switch 240v or 24 v, no need to worry