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

Swapping mechanical to digital thermostat

Discussion in 'Plumbing and Central Heating' started by BLM007, 26 Dec 2020.

  1. BLM007

    BLM007

    Joined:
    26 Dec 2020
    Messages:
    6
    Thanks Received:
    0
    Country:
    United Kingdom
    Morning all, and merry Christmas.
    I am looking to replace my old sangamo choice rstat1 with a moes but-002 go. A bit of back ground. Downstairs we have water underfloor heating upstairs there are radiators. I have 4 room stats downstairs and leave the boiler on all. The time and control the temp via room stats and this works well. The problem is that the upstairs has only a mechanical thermostatic switch that we now need to manually adjust when we want the radiators to come on. I wanted to switch to a moes but 002 to be able to set a timer for this. I am a bit lost on the wiring. The sangamo has a live and live switch connected with the neural not connected. The bht 002 needs all 4. I have connected the live at the boiler and can get bht operational but cannot get the heating to operate. I have 240 v on live and neural, and live switch but i cannot get heating on. Any ideas ?
    9D087A0F-14C2-4338-9506-39C1C105D5FE.jpeg
     
    Last edited: 26 Dec 2020
  2. Sponsored Links
  3. ianmcd

    ianmcd

    Joined:
    15 Aug 2010
    Messages:
    23,951
    Thanks Received:
    10,046
    Location:
    Livingston
    Country:
    United Kingdom
    your thermostat does not connect to the boiler in any way, it gets wired to the zone valve controlling that zone , the valve tells the boiler when to come on
     
  4. BLM007

    BLM007

    Joined:
    26 Dec 2020
    Messages:
    6
    Thanks Received:
    0
    Country:
    United Kingdom
    Ian thanks, you are correct it does not need connected to the boiler. I grouped it in with other neutrals to get power to moes thermo, otherwise it does not power up. I can hear the moes switch “click” when adjusting temp but the valve at boiler does not move.
     
  5. ianmcd

    ianmcd

    Joined:
    15 Aug 2010
    Messages:
    23,951
    Thanks Received:
    10,046
    Location:
    Livingston
    Country:
    United Kingdom
    post a pic of what you have done with the new thermostat
     
  6. BLM007

    BLM007

    Joined:
    26 Dec 2020
    Messages:
    6
    Thanks Received:
    0
    Country:
    United Kingdom
    Ian, please see below, colours are as per picture above. The Boiler end i have but notes as to where the cables are. C6BB3CB5-7EBB-45FA-B2AF-9F75EFD73627.jpeg FDDFCB33-6664-4992-AC9A-F12F6D9A6086.jpeg
     
  7. Sponsored Links
  8. stem

    stem

    Joined:
    20 Jul 2005
    Messages:
    6,842
    Thanks Received:
    1,637
    Location:
    Nottinghamshire
    Country:
    United Kingdom
    For 230V motorised valve control, the new stat replaces the Honeywell as follows:

    Brown wire (Live) in Honeywell 1, goes to new stat L 4

    Grey (Switched live) wire in Honeywell 3, goes to new stat 2

    Insert a link between new stat 4 and 1 so that the two terminals are joined together.

    The black wire needs to become a neutral connection. So assuming that these are both ends of the same wire....

    2.jpeg

    ....then the thermostat end connects to the new stat N 3, and the other end to an existing neutral connection. Ideally a blue sleeve should be slid over each end to show that it is being used as a neutral connection.
     
    • Like Like x 1
  9. BLM007

    BLM007

    Joined:
    26 Dec 2020
    Messages:
    6
    Thanks Received:
    0
    Country:
    United Kingdom
    Ian, you are a star, worked a treat, many thanks.
     
  10. ianmcd

    ianmcd

    Joined:
    15 Aug 2010
    Messages:
    23,951
    Thanks Received:
    10,046
    Location:
    Livingston
    Country:
    United Kingdom
    Thanks but that was @stem and not me
     
  11. stem

    stem

    Joined:
    20 Jul 2005
    Messages:
    6,842
    Thanks Received:
    1,637
    Location:
    Nottinghamshire
    Country:
    United Kingdom
    I'm sure you would have given the same advice (y)
     
    • Thanks Thanks x 1
  12. BLM007

    BLM007

    Joined:
    26 Dec 2020
    Messages:
    6
    Thanks Received:
    0
    Country:
    United Kingdom
    STEM, many thanks, worked a treat.
     
    • Like Like x 2
  13. 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