Zone valve wiring

Discussion in 'Plumbers' Talk' started by Rmprop, Aug 15, 2016.

  1. Rmprop

    Rmprop Member

    I have a 3 story old house with with cast iron rads and manual valves and one bedroom on the top floor which gets pretty warm when the heatings on. I spoke to a plumber who said I could add a zone valve and room stat to shut that area off when it gets up to temp, like a trv I suppose.

    He recomended a 2 port EPH Detach Pro and EPH Combi Thermostat manual dial stat. I've bought both of them and just wondering how they should be wired so they work independantly of the boiler (the boiler was its own wireless stat on the ground floor).

    The instructions are vague for the valve, it has 5 wires - blue, brown, grey, orange and earth. The stat has no wiring info at all. Also, what size cable is needed between the valve and stat?

    Anyone point me in the right direction? I'm sure if you're a plumber then it's straight forward, but I'm a welder…
     
  2. leesparkykent

    leesparkykent Well-Known Member

    how far is the zone valve going to be from the wiring centre/boiler?
     
  3. Rmprop

    Rmprop Member

    The boilers in the cellar and running wires to it would be a stupid amount of work. I dont want it to control the boiler anyway, just issolate the one rad on the top floor when it gets warm up there
     
  4. sam spade

    sam spade Active Member

    Why not just fit a TRV and set it to a low temperature?
     
    TheMorg likes this.
  5. nigel willson

    nigel willson Screwfix Select

    problem is youre not supposed to control anthing on a heating system unless its all from the same supply. However i dont suppose this particular one will cause a prob.All you need to di is plug into local socket, and wire it so that the stat powers up the supply wires to valve motor, thats the brown and blue + earth. you dont need the orange and grey. you will have to sort the switching out so that it is off ie not powered up when you want to turn the rad off, and powered up when you want it on. This due to the valve being a powered opening one. it will be shut when no power is applied. hope that helps
     
  6. Glad its Friday

    Glad its Friday Active Member

    Get someone in who knows how to wire it up.

    You run the risk of electrocuting someone or yourself if you don't know where all the wires go.

    Nigel's advise above is not good - when you turn the power off at the fused spur then the whole system should be isolated. Think about a diyer like yourself trying to sort something out in a few years time and getting a shock because your system is fed by 2 supplies :(
     
  7. Rmprop

    Rmprop Member

    I understand your point, but I'm not a diyer, I've just never wired a zone valve, just like every other plumber hadn't at some point in their life, but it was ok for them to ask the question once.

    If plumbers were reliable I might ask one to do it for me.
     
  8. TheMorg

    TheMorg Active Member

    Why can't a TRV be fitted?
     
  9. Rmprop

    Rmprop Member

    It can but we want to keep the valves that are already on the rad, its an old cast iron one
     
  10. For God's sake don't get a plumber to wire it up for you. You need a decent electrician!
    Joking apart, Friday's advice should be followed.
     
  11. Glad its Friday

    Glad its Friday Active Member

    I didn't say get a plumber to wire it up, I said get someone who knows how to do it. That maybe a plumber or electrician, but yes, someone reliable.
    I learnt by going to college (a very long time ago!) - not winging it.
     
  12. Rmprop

    Rmprop Member

    Im not winging it. I was told by a plumber it can be done and was straight forward to do, now I'm asking how it is done. Whether you were taught at college or asked on a forum full of experienced people, I'm asking the question so I too can learn just like you did.
     
  13. longboat

    longboat Screwfix Select

    You can get TRV's to suit many traditional styles. Have a looks on google, wiring and plumbing in a zone valve for one rad is lunacy.
    Just get a matching trv and lock-shield that compliments your cast iron rad. ;-)
     
  14. Pollowick

    Pollowick Screwfix Select

    Or what about just having a TRV on the flow with the output side of the TRV being adapted back to 15mm copper rather than a radiator? Not conventional but easier to install than a zone valve, no electrics, no changes to the existing radiator and if the OP is competent with compression joints then a fairly simple task he can do himself.
     
    Deleted member 33931 and kiaora like this.
  15. Rm, wiring this is dead easy, but you still shouldn't do it.

    The 2-port valve has lots of wires, but only two for the motor that operates it (and an earth).

    The 'stat has lots of wires too, but only two which act as the 'switch' you need.

    So, it's as easy as wiring a switch to an electrical device.

    Except, the warnings given above about having the complete CH system isolated at a SINGLE point is legit. It is not only very dangerous to not to, but also breaks the leccy regs.

    And, if your 'stat is the electro-mechanical type wot uses accelerator resistor inside, then the wiring is slightly more tricky. But only slightly.

    There, that's all I'm saying :p

    'Cos you shouldn't be doing this at all (regs), and if you cannot wire what is effectively a switch controlling a simple 240V device, then you definitely shouldn't be doing this at all.

    People doing wiring - even basic wiring - should 'understand' what it is they are doing. They'd be nuts to, say, wire a lighting circuit using JBs or 'loop-in' if they were just following a diagram and hoping for the best; they should understand what it is each wire does.

    You have the wiring diagrams for both these devices.

    But you still shouldn't do it.

    Having zoned areas is great. But they should be done properly, and that usually means a zone being, say, all the bedrooms, or all of an upstairs level. And always as part of the whole CH leccy system, supplied from one point.

    There's got to be a simpler solution?
     
  16. Cracking idea.

    Wherever you were planning to fit the zone valve (where you'd need access to the pipework in any case) instead divert the flow (or return if it's easier) pipe neatly to a point where you can fit the TRV above floor level, even in the hallway outside. I guess it would need to be comfortably above floor level so's to avoid floor-level draughts? So at the height they'd be at on a rad at least.

    http://www.screwfix.com/p/chrome-st...tracking url&gclid=CNDqh8q4xc4CFRcTGwodWS8CtQ
     
  17. TheMorg

    TheMorg Active Member

    You can also get TRVs with a remote sensor. Something like a Danfoss 013G5062.
     
  18. Pollowick

    Pollowick Screwfix Select


    That will still need a valve body, but it would be a neater variation - hidden valve and accessible sensor. And no power either!
     

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