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Wiring up a Wireless Thermostat

Discussion in 'Electrics UK' started by Extooth, 18 Apr 2017.

  1. Extooth

    Extooth

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    Hi,

    I can't get my head around this and I'm wondering if any of you can help me out. I currently have a Worcester Heatslave 15/19 Oil Boiler, it is controlled with a Programmer in the Kitchen, where I can tell both the Hot Water and Heating to come on, and set times for weekdays and weekends. Strangely, there's also a ETS 1 Lifestyle Thermostat in the Boiler room. (not the best location) I have bought a Center Wireless thermostat in order to better manage my heating and to hopefully save some Oil. I want to keep the programmer in the Kitchen as it also controls the water.The RF unit (BDR91) needs to be installed near to the boiler. I Imagined the Wiring would simply replace the current thermostat but it doesn't look so easy. Will upload several pictures to illustrate. Can anyone help with my wiring? Is it possible?

    Edit: After taking a look at PCB for the Boiler, the thermostat next to the boiler turns out to be a Frost stat with the wrong facia - I'm guessing the previous owner wanted to use up supplies! Ideally, I'd like to keep it there.

    So, the current situation is as follows, My Kitchen 7day programmer currently calls for heat and water when I press a button or during certain times during the day. I have a Programmable Thermostat that I would like to use in order to be more efficient and have better control.

    Is It possible to use both programmers? I need the kitchen one in order to call for Hot Water. The Heating would I guess be left on constant, but the actual say would come from the programmable thermostat as to whether it is on or not.

    If so, how would the wiring work look? I've uploaded the boiler diagram and that of the programmable thermostat.

    Many thanks!
    DSC_0030.JPG DSC_0034.JPG eeeerty.JPG Untitled.png
     
    Last edited: 19 Apr 2017
  2. ericmark

    ericmark

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    The L and N stand for Line and Neutral although normally taken from same supply as boiler, it could be a simple 13A plug. The A,B, and C the C stands for common and the B normally open so old thermostat wires go to B and C.

    As to how to set up, when the condensate boiler came out, the whole system changed, so need to know which, if pre condensate then simple thermostat is great, but if condensate then the thermostatic radiator valve (TRV) should control things until into summer months, the wall thermostat turns off the system in summer but does not control in winter, all down to the hysteresis caused by wall thermostat.

    I think some one has been very naughty and the green/yellow and brown go to B and C a link from C brown to L and the blue on to N neutral, this breaks the rules one should not use green/yellow for anything other than earth, but it seems they have.
     
  3. Extooth

    Extooth

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    Can't I simply use the 3 wires in the old thermostat to power the wireless receiver? Its getting power already isn't it? What's slightly confusing also are the sleeve colours, for some reason the earth sleeve seems to be connected to terminal 2.
     
  4. ban-all-sheds

    ban-all-sheds

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    [​IMG]

    [​IMG] [​IMG] [​IMG] [​IMG]

    Can you say stupid, ignorant, dangerous, f***wit plumber?
     
  5. Extooth

    Extooth

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    I can. Its annoying to see, the previous owner is a tradesman and he did everything himself.. Hope this is only 1 example of poor workmanship. :l
     
  6. ban-all-sheds

    ban-all-sheds

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    Be very afraid.

    If he did that, then he could have done anything - once you start down the slippery slope of DGAS f***wittedness there is no way to stop sliding.
     
  7. Extooth

    Extooth

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    The Current setup is working as intended, is he simply using the wrong cable for the job and didn't bother putting a sleeve on the wire? This makes matters so much more confusing... :S
     
  8. endecotp

    endecotp

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    Sort of, except that you're not allowed to over-sleeve green/yellow earth wires.
    And even if you were allowed to, it would still mean that there isn't an actual earth present - observe that the next terminal down has an earth symbol, and is 't connected to anything.

    The implication is that you now cannot trust that any wires anywhere in the house do what you think they do :( and will have to be very careful (and paranoid) with anything that you work on.
     
  9. Extooth

    Extooth

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    Well, fml >< So in terms of making the above work, what cable should I buy? I'm confident I can get this to work, its just something I've not done before. Any Thoughts?
     
  10. endecotp

    endecotp

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    3 core + earth.

    (Edit: I think. That's what you'd need to do the old termostat correctly. I've not followed what the replacement needs, if that's any different.)
     
  11. stillp

    stillp

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    Are you sure Eric? Looks to me like A = Common, B = Normally Open, C = Normally Closed.
     
  12. Extooth

    Extooth

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    appreciate your help. I will change the wire soon, hopefully will figure out the new stat also. Time to pray the pcb wiring is done correctly :eek:
     
  13. ericmark

    ericmark

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    Re-looking at diagram seems your right need to use A and B leave C disconnected.

    514.4.2 Protective conductor
    The bi-colour combination green-and-yellow shall be used exclusively for identification of a protective conductor and this combination shall not be used for any other Purpose.
    Single-core cables that are Coloured green-and-yellow throughout their length shall only be used as a protective conductor and shall not be over-marked at their terminations, except as permitted by Regulation 514.4.3.
    In this combination one of the colours shall cover at least 30 % and at most 70 % of the surface being coloured, while the other colour shall cover the remainder of the surface.
    A bare conductor or busbar used as a protective conductor shall be identified. where necessary, by equal green-and yellow stripes, each not less than 15 mm and not more than 100 mm wide, close together, either throughout the length of the conductor or in each compartment and unit and at each accessible position. If adhesive tape is used, it shall be bi-coloured.

    This is the old regulation one could say since it states "single core cables" that other cables can be over marked, however I would say that's very bad practice.

    If it was my house I would be looking at a battery powered thermostat, then there is no need for a neutral, which means you have enough cables without getting a new cable drawn in.
     
    Last edited: 18 Apr 2017
  14. Extooth

    Extooth

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    Edit: Edit: After taking a look at PCB for the Boiler, the thermostat next to the boiler turns out to be a Frost stat with the wrong facia - I'm guessing the previous owner wanted to use up supplies! Ideally, I'd like to keep it there.

    So, the current situation is as follows, My Kitchen 7day programmer currently calls for heat and water when I press a button or during certain times during the day. I have a Programmable Thermostat that I would like to use in order to be more efficient and have better control.

    Is It possible to use both programmers? I need the kitchen one in order to call for Hot Water. The Heating would I guess be left on constant, but the actual say would come from the programmable thermostat as to whether it is on or not.

    If so, how would the wiring work look? I've uploaded the boiler diagram and that of the programmable thermostat.
     
    Last edited: 19 Apr 2017
  15. ericmark

    ericmark

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    I don't know how your boiler is connected, a typical arrangement would be [​IMG] you will note the thermostat moves the three position valve, brown/white (HTG call) then the valve fires up the boiler. This is one of many options, it depends how the domestic hot water is heated, it can be pumped as shown, or it can be thermosyphon and Honeywell one of the well known central heating parts manufacturers did a series of plans, they had letters like the Y plan or S plan or C plan or S plan. This is not how the boiler is internally wired it's how the house is wired, so quoting the boiler make and part number does not really help.

    With latter boilers the domestic water and central heating is done directly by the boiler so far easier. In fact with modern condensate boilers the room thermostat is not required, the TRV controls the room temperature in theory, however in practice the room thermostat is still used to switch off the system in the summer, I have just fitted a new TRV and reason I am up is to see if the valve controls hall temperature when the central heating fires up. Hall at 17.3°C outside at 7.7°C and still waiting for it to fire up.
     
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