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Help setting up the Nest Learning Thermostat 3rd Generation

Discussion in 'Plumbing and Central Heating' started by Jemmalb, 16 Oct 2020.

  1. Jemmalb

    Jemmalb

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    Hi,

    I'm trying to replace my old heating system (Danfoss) with the Nest learning thermostat (3rd generation).

    I have removed the programmer (FP/CP715-Si) from the wall and it shows the following wires (please see attached image)
    3 x going into live (L)
    3 x going into neutral (N)
    1 x going into DHW ON (3)
    1 x going into HTG ON (4)

    I have a combi boiler on the ground floor with a hot water tank on the first floor.

    I believe the 3 L and 3 N to go to the L and N on the Nest heat link. The DHW to 6 on the heat link and HTG to 3. However, the 3 L wires and 3 N wires dont fit into the same port.

    Any help will be greatly appreciated.

    Many thanks :)
     
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  3. ianmcd

    ianmcd

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    join the 3 wires into a terminal strip connector and take a single wire out of the other end to the hive
     
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  4. Jemmalb

    Jemmalb

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    Thank you, ive done that and it lights up but it doesn't seem to control the heating
     
  5. muggles

    muggles

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    Photo?
     
  6. Jemmalb

    Jemmalb

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    So the first picture is what my heating system looked like before hand and the second shows what has been done to get it to turn on. I've connected the 3 live into a 4 port push in connector and then I've rang a wire from the 4th port into the nest heat link, I've done the same with neutral and then HTG to port 2 (didn't work in port 3) and DHW is in port 5 (didn't work in port 6).

    The heat link lights came on and I connected it to the thermostat but no heating. When you turn the manual button on it doesn't turn the heating on at the boiler.
     

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  7. muggles

    muggles

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    Move HTG back to 3 and DHW back to 6 - that's where they're supposed to be. You need to put links in between L, 2, & 5
     
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