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Replacing 3-way valve in wood-pellet boiler system

Discussion in 'Plumbing and Central Heating' started by thelaughingbadger, 28 Sep 2015.

  1. thelaughingbadger

    thelaughingbadger

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    Hi All

    My first post here but I'm looking for a bit of advice (I am a willing novice). I've a wood-pellet boiler and thermal store in the garage. It provides hot water through the radiators in the house and feeds the hot water tank in the loft, where the header tank is. There are no other heat sources.

    The three-way valve in the garage is leaking (not the connections but the valve itself). I attach a couple of pictures where you can hopefully see the set-up in the garage around the faulty valve in question (the one behind the automix). I have a replacement valve but I am just not too sure how to replace it in terms of whether I need to drain the whole system first or if there is some way of minimising the amount of draining etc. that I have to do.

    Any hints, tips or ideas would be very much appreciated. Happy to provide clarification if none of this makes sense!

    Thanks in advance

    Ben
     

    Attached Files:

  2. muggles

    muggles

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    Your pics haven't attached properly - they're in a *.zip format and there's no chance I'm opening that! Try posting JPEGs
     
  3. thelaughingbadger

    thelaughingbadger

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    ... and now with pictures (thank you Andrew!)
    IMG-20150928-00087.jpg IMG-20150928-00087.jpg IMG-20150928-00088.jpg
     
  4. Agile

    Agile

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    Looks like some kind of proportional mixing valve.

    Also seems the pump has been leaking as well.

    Tony
     
  5. Corgigrouch

    Corgigrouch

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    Indeed, that's an electrically operated thermostatic blending valve.... Looks like a drain down
     
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  6. Agile

    Agile

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    That's better.

    I did try to open it but WinZip is a chargeable program now and I don't really need it.

    Tony
     
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  7. thelaughingbadger

    thelaughingbadger

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    I think the pump is fine (it's just some crud stuck to the front). So, no other way than to drain everything down? Assume that means thermal store, radiators and water to the hot water tank?
     
  8. manortim

    manortim

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    Drain down. Also, change the pump valves at same time. The type you've got a leaks waiting to happen.

    Remember to buy a large volume of inhibitor to add once it'd been refilled and operating for a few days without fault.
     
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  9. JonG1

    JonG1

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    Ben have you checked that there are no isolation valves on the flow, to and from the valve and the return connection, you have got the pump isolation valve (but wouldn't trust it).

    If you can post additional pictures or draw up a schematic there may be an easier option.
     
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  10. thelaughingbadger

    thelaughingbadger

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    Thanks for all advice so far - will try to get more pics/sketch out system later in week (I've very cleverly managed to knacker my foot today!)
     
  11. PullerGas

    PullerGas

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    Why not email them & see if there's a washer set available
    http://www.dvcenter.dk/media/uploads/automixctr.pdf

    If you drain the system down, be sure to cut in some valves too. The pump ball valves are mince, they'll soon leak also. Love the T&E wire to the circulation pump!!.........quality job??!!!......:LOL::LOL::LOL:
     
  12. JohnHarrison

    JohnHarrison

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    It is a mixing valve. Change the valve. Some makers have kits that only replace the sealing glands, which are cheap. Check before buying a whole new valve. Do not change the actuator.
     
    Last edited: 30 Sep 2015
  13. JohnHarrison

    JohnHarrison

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    Yes. use pump adapters and a full flow ball valve on each side. Those valves act as restrictions.
     
  14. thelaughingbadger

    thelaughingbadger

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    Hello all

    Managed to roughly map what is going on - hope it makes sense. Have not managed to map whole system, just the boiler and thermal store. These then link to system in loft (header tank, hot water storage tank). Could not see any isolation valves other than those on either side of the pump (I note comments re. not trusting these). Quite happy with idea of cutting in new valves - assuming one each on C and D and possibly to left of faulty valve? What I'm not quite sure of is where A -D lead to/from and direction of flow. And not clear as to what process of draining down would be.

    upload_2015-10-3_10-51-1.png
     
  15. Mechanical Matt

    Mechanical Matt

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    Please can you provide additional information on your current system setup.

    1- make and model of pellet boiler
    2- make and size of thermal store
    3- what heat emitters you have in the property.
    4- additional pics of pipe work from boiler to store and from store to property.
     
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