1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

Nest Thermostat E with Honeywell CM900

Discussion in 'Plumbing and Central Heating' started by singh01211, 5 Jul 2019.

  1. singh01211

    singh01211

    Joined:
    5 Jul 2019
    Messages:
    2
    Thanks Received:
    1
    Country:
    United Kingdom
    Hi,

    I’d like to apologise in advance as I’m a complete novice to this stuff. I’m trying to learn how to do wiring/installations and not rely on someone doing it for me so please be patient with me.

    I’ve bought the new Nest Thermostat E to replace my Honeywell CM927 controller. I’ve located the receiver for the controller which is next to my boiler. When I went to install the new Heatlink E which came with the Nest E, the wire labels weren’t the same.

    So my Honeywell receiver has wires for L N and then A B. The Heatlink E asks me for a C and NO wire. Through doing some research online, I’ve found that the A wire is the C and the B wire is the NO. My only question is, what happens with the L and N wire. Are they the power source to the receiver and will not plugging them into my Heatlink do anything? (Pics below)

    Sorry if I the question I asked is simple, just trying to learn how this all works for the future. Thank you all

    Honeywell receiver
    71C73ABC-03C0-48F5-86C4-BF0BEE4AEF20.jpeg

    Heatlink E
    FC4CE19F-8A41-4740-924B-F0E7111EE264.jpeg
     
  2. ianmcd

    ianmcd

    Joined:
    15 Aug 2010
    Messages:
    11,029
    Thanks Received:
    3,125
    Location:
    Lanarkshire
    Country:
    United Kingdom
    Your Honeywell required a L&N to power it, your nestE uses 2x Batteries you will have to isolate the L&N and just use the two switching wires as you described in your post
     
    • Like Like x 3
  3. singh01211

    singh01211

    Joined:
    5 Jul 2019
    Messages:
    2
    Thanks Received:
    1
    Country:
    United Kingdom
    Thank you mate, I appreciate your reply.
     
    • Thanks Thanks x 1
    • Like Like x 1
Loading...

Share This Page