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

Help Needed - Nest Thermostat replacing a Danfoss TP9000

Discussion in 'Plumbing and Central Heating' started by SirMario, 8 Apr 2020.

  1. SirMario

    SirMario

    Joined:
    8 Apr 2020
    Messages:
    4
    Thanks Received:
    0
    Country:
    United Kingdom
    I have been spending a lot of time at home (due to the coronavirus epidemic), and I decided to take the plunge, learn something new and replaced my Danfoss TP9000 with a nest thermostat 3rd generation.

    After reading a lot of forum and posts online I was pretty confident that it would be easy swap and all would be sorted after 1 hour. How wrong I was...

    The Danfoss box the cables were too short and that made it difficult just to connect them all correctly, after a couple of hours all the cables connected correctly and all kicked started as planned. But I quickly realised I had a problem, the boiler was constantly heating the hot water, and unfortunately, I was not able to find a solution online, so I'm hoping that someone had the same issue as me.

    My configuration is as follows:

    Danfoss TP9000 w/ Thermostat

    Boiler Ideal Logic heat H12

    I have put the danfoss back in place as the missus was complaining, but I really don't want to be defeated and pay £85 quid for a professional installer.

    Any suggestions are appreciated
     

    Attached Files:

  2. Sponsored Links
  3. picasso

    picasso

    Joined:
    8 Apr 2008
    Messages:
    10,117
    Thanks Received:
    2,459
    Location:
    Essex
    Country:
    United Kingdom
    We need to know how you connected the nest to see where you have gone wrong, can you post a pic or diagram ?
     
  4. SirMario

    SirMario

    Joined:
    8 Apr 2020
    Messages:
    4
    Thanks Received:
    0
    Country:
    United Kingdom
    I have dismantled it and replaced it with my the old thermostat, however, I have followed the below diagram and ended up with the same Heat Link as per picture.

    I also have a system boiler, with a water tank if it makes a difference.

    Thanks

    S plan 1.png splan 2.jpg splan 3.jpg
     
  5. picasso

    picasso

    Joined:
    8 Apr 2008
    Messages:
    10,117
    Thanks Received:
    2,459
    Location:
    Essex
    Country:
    United Kingdom
    The black wire in the original pic is hot water on but on the nest you have a black connected to heating on, do you have the heating on and hot water on reversed ?
     
    • Thanks Thanks x 1
  6. SirMario

    SirMario

    Joined:
    8 Apr 2020
    Messages:
    4
    Thanks Received:
    0
    Country:
    United Kingdom
    I will try to install it again tonight, I shall take pictures of it
     
    • Like Like x 1
  7. Sponsored Links
  8. Chris_W

    Chris_W

    Joined:
    26 Sep 2019
    Messages:
    3,678
    Thanks Received:
    972
    Location:
    North
    Country:
    United Kingdom
    I have noticed you have a grey wire for hot water call, which appears to be connected to neutral on the Danfoss? Also the wiring going to t1 and t2 look a different colour than original, although could be lighting?
     
  9. SirMario

    SirMario

    Joined:
    8 Apr 2020
    Messages:
    4
    Thanks Received:
    0
    Country:
    United Kingdom
    Just messed around with it again. And I found out the constant hot water issue. It was the salmonella prevention system that always heats up the boiler to kill the bateria. Because I was always turning the thermostat off it restarted again the procedure.

    Problem solved.

    Cheers for your help and input, I'm much appreciated.

    Stay safe
     
    • Like Like x 1
  10. picasso

    picasso

    Joined:
    8 Apr 2008
    Messages:
    10,117
    Thanks Received:
    2,459
    Location:
    Essex
    Country:
    United Kingdom
    Thanks for the feedback.
     
  11. ericmark

    ericmark

    Joined:
    27 Jan 2008
    Messages:
    16,262
    Thanks Received:
    1,474
    Location:
    Llanfair Caereinion, Nr Welshpool
    Country:
    United Kingdom
    I had same problem, it can be turned off, but the help line did not seem to know what was happening.
     
  12. DIYnot Local

    DIYnot Local

    Joined:
    3 Sep 2019
    Country:
    United Kingdom

    If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

    Select the supplier or trade you require, enter your location to begin your search.


    Are you a trade or supplier? You can create your listing free at DIYnot Local

     
Loading...

Share This Page