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Microbore balancing query

Discussion in 'Plumbing and Central Heating' started by Bilco21, 1 Sep 2012.

  1. Bilco21

    Bilco21

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    Hi all,
    I live in a 3 bedroom semi detatched new build house with a sealed system, condensing boiler ( ideal icos he15) and 10mm microbore plastic heating pipe system.
    I was wondering wether or not this requires balancing as our friends who live in a house identical to ours their heating system has every single radiator lockshield valve fully open on all Rads.
    Our heating system has the pump on speed 3 (myson CP53) Auto bypass valve on 1.5 (honeywell DU145) and the rads are fully open downstairs and about half open upstairs. However after many hours of reading info on the net i wonder wether the system is set up correctly as i know only to well what new builds by persimmon are like and the fact that our friends house is completely different set up to ours. I wonder wether our pump speed is too high and if our rads need to be finely balanced as i have heard that microbore is nearly self balancing or wether i should open the lock shields fully like our friends. I also wonder about the auto bypass valve is it too lower a setting??? Any help is very much appreciated, Many thanks Will
     
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  3. Armo74

    Armo74

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    Are you having any problems with the system? System noise?
    Radiators not heating up? Are you sure your not getting the valves mixed up, the lockshields are there for balancing purposes.
     
  4. ianmcd

    ianmcd

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    your auto BY Pass will have manufacturers instructions if not supplied will be available on line but you will need to look at your boiler manus info to decide what the setting should be, balancing rad flow sounds easy but really needs a pro to do it properly and I stress a pro not just anyone I would expect a charge of £300 to balance a 7rad system properly, needs expensive equipment and proper knowledge
     
  5. Bilco21

    Bilco21

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    Armo74- our house just doesn't seem to heat up as quick as there's and always seems slow to warm and I just wondered if it because all their lock shields are wide open I'm defo certain it's the lock shields fully open and not the trv's I just wanted to kno if this was as effiecent as both houses are completely identical!
    Ianmcd- I realise that the auto bypass is to bet set as per boiler minimum flow rates required I wouldn't dream of touching or adjusting that as I'm not competent I just wanted to ask the professionals if you thought the setup was correct and as mentioned above why are both house's rads balanced so differently?? Thanks guys
     
  6. DP

    DP

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    Bilco,

    The boiler will have two 22mm pipes that feed the radiators and cylinder. When the boiler has been running for say half an hour, the right hand pipe will be hot and the left not as hot. A rule of thumb would be, you will not be able to hold the pipe on the right but will the pipe on the left (refering to two pipes located top right of boiler)

    With all TRVs open fully and system 'up to temperature', carry out above test on each radiator and two pipes that connect to cylinder indirect coil. Similar results should be the case as when 'testing' the boiler flow and return pipes.

    The bypass will be hot one side and cool opposite side when calling for heat or heating water. The function of this valve is to stay closed and only open if circulation through the primary loop is too high (almost no circulation through primary circuit due to motorised valves shutting down or hardly any flow through TRVs)

    If a radiator has 'hot' pipe one side and similarly hot pipe the other connection, close the radiator lockshield valve a tad and continue testing. If temperature difference is too great, open the lockshiel valve a tad.

    Ianmcd, what equipment are you refering to? Genuine interest, not a dig :unsure:
     
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  7. dcawkwell

    dcawkwell

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    All systems need to be balanced to work at their best.
    You friends house has either been redecorated and they
    took the radiators off and put them back on fully open not knowing
    any better.
    Or was installed by a heating engineer who didn't know any better.

    Just been to a house where the owner was complaining one of the radiators
    wasn't heating up properly.
    Easy fix all the radiator valves were fully open.

    Water finds it easiest path. Don't care what sort of system it is.
     
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  8. Agile

    Agile

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    Microbore is largely self balancing because the pipe resistance is significant in series with each rad.


    Because the microbore resistance is higher than a standard system the pressure across the system will be higher and whilst an ABV setting of 1.5 would be about right on a standard system I woulod expect yours to need a higher setting perhaps 2.0 or 2.5

    Apart from increasing the ABV setting, I dont see there is anything you need to do unless you really hava a problem.

    Tony Glazier
     
  9. ianmcd

    ianmcd

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    dcawkwell is correct in that water is completely lazy like anything else and will always take the easiest way through your system, if it can just flow through your very small bathroom radiator rather than your large lounge radiator it will do so , to balance your system is to make the water flow equally through all waterways a digital flow and return temp thermometer is required but to be honest a really experienced engineer will do it by hand
     
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  11. Armo74

    Armo74

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    The system should be balanced correctly via the lockshield valves, as said above you only normally come across lockshields fully open if a radiator has been taken off for say decorating purposes and the person putting it back on doesn't realise what there purpose is. When removing a radiator you should make a mental note of how many turns the lockshield valve took to close completely. When balancing the system there are design flow and return temperatures that have to be adhered to,you will find the first lockshield on the circuit almost closed and the last almost fully open.
     
  12. Nige F

    Nige F

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    and then want £300 in his hand :mrgreen:
     
  13. Bilco21

    Bilco21

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    That's what I don't understand with their lock shields be fully open, they definetely haven't had the rads of because of the property being a new build and they have only been in for 8 months ( no decorating done yet). I just wonder with the small ID of microbore pipes wether our rads are being restricted by having the lockshields closed slightly, as opposed to fully open. As I mentioned earlier our rads seem to be slower to heat up than theirs. I'm pretty confident that neither house has been commissioned or setup correctly having had experience with persimmon and knowing their workmanship. Could radiators be restricted to much and not get enough water flow through them making the heating slower to warm up????
     
  14. Armo74

    Armo74

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    Hence the need for correct balancing, either have a go yourself plenty of info on it in the FAQ's or get someone in if your not happy.
     
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  15. DP

    DP

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    OP, I wonder what the thank you button is for or why the site owners went to some trouble to put it there. Now that various professionals have posted to increase your knowledge of balancing of central heating systems, I wonder if they should also thank you for starting this thread :rolleyes:
     
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  16. hansthebear

    hansthebear

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    Sarky comments like that really increase the warmth and loving on this forum i think.
     
  17. DP

    DP

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    If I was looking for warmth and love, I certainly would not be trawling DIYNOT pages. It is common curtesy to thank someone who has offered help and assistance. Perhaps the bear thinks differently.

    Posters come here with all sorts of problems. Some posts leave a lot to be desired. To reply to these is headbutting a brick wall.

    This post needed the fog to be cleared. I am confidant the poster will be able to balance the installation based on advice given by those that do this type of work for a living :) .

    Let it also be said, there are pros who choose NOT to post in the plumbing section for the abuse or grief they get:cool:
     
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