Recent content by Glanmor

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    Gravity Hot Water circulation

    I promised to update on this. Some good news and some bad… Good news is that its working now. Bad news is that I don’t know why. I repeated all of the suggestions you gave several times since the last post but nothing changing. Isolated the Cylinder coil by cutting pipes (cylinder flow and...
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    Gravity Hot Water circulation

    update... still stuck, no change. Thanks to all the guys who responded since last post. Chrisw99, thanks for extra effort of printing out the manual page. I have since cut Cylinder return pipe (pipe D) and now 100% sure there is no blockage in the Coil. Tried loosening top union as suggested by...
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    Gravity Hot Water circulation

    Hi All just dug out something that might be causing circulation issues for me. Its some kind of valve attched to the veritcal Flow pipe (pipe C in previous pic) and its half way up the wall from where the Boiler is. Does anyone identify what this valve is please: It appears to be an in-line...
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    Central Heating OK, Hot Water Circuit Cold

    Mike2007, this system has served well in the last 19 years - without any issues. It was given the usual Summer break, no CE or hot water required. Just moved/slide the control switches to OFF position. End of Summer I tried HOT-WATER only switch and boiler responds but not sending hot water up...
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    Gravity Hot Water circulation

    Hi Had another go at this last night. I can now say that the WATER circuit looks like this pic below. I have omitted the CENTRAL HEATING circuit on the right hand side of the boiler. With hose pipe on draincock A (incidently this is not the Bolier draincock, that is a seprate one further down...
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    Gravity Hot Water circulation

    Sorry for no update/feedback. Couldnt get chance to have a another go. I will report back here. Cheers
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    Central Heating OK, Hot Water Circuit Cold

    Hi Mike2007, its a 4 pipe BBU, 2 x Pipes service Central Heating and 2 x Pipes service water-only circuit. It is an old system, Glowworm 246 I think. Thanks for looking.
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    Gravity Hot Water circulation

    When the pump is running, the pressure at boiler return is higher than at flow, due to the boiler headloss. This tends to cause flow in the "wrong" direction through the coil. But on a big old boiler headloss won't be much, maybe only ~ 0.2m, clearly not enough to cure the problem. Fixitflav...
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    Gravity Hot Water circulation

    Servotech, I had considered the 'good boild up' method but scared that it might introduce another serious issue and possibly loose the precious Central Heating which is working perfectly at present. In trying to understand physics behind over-boil method - I can see that on the WATER-ONLY...
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    Gravity Hot Water circulation

    Nige F & Servotech - Flow pipe from BBU to Cylinder is indeed 28mm, so is the Return, but I think there is a 'flat' area. BBU is on ground floor. Flow pipe goes up one wall (say 2.5m high) into the ceiling, then crosses (say 4m) under floor of the upper Rooms to the opposite wall and into the...
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    Gravity Hot Water circulation

    Sorry ianmcd, just saw your last response. I considered slackening upper pipe on the coil but gum on that union is as hard as solder now. As mentioned to fixitflav I cut that pipe last week to enable propper flush of the coil, now wish I fitted bleed point there whilst I was at it. I will try...
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    Gravity Hot Water circulation

    There is no bleed point on or near the cylinder primary. Infact, in an attempt to get circulation going I cut cylinder upper pipe last week in order to facilitate a propper/sure flush of the cylinder coil, thinking a block in the coild was preventing it. I wish I fitted a bleed point then. No...
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    Gravity Hot Water circulation

    Have central heating from same boiler, it is pumped and it works perfect. All radiators full. I tried bleeding/re-filling entire circuit from lowest radiator draincock using mains water but no joy. Tried bleed/re-fill from draincock on hot water side return pipe fitted close to boiler using...
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    Gravity Hot Water circulation

    ianmcd, thanks for looking into this. Flow pipe from Boiler clear all the way upto arching vent in the F&E tank F&E Feed clear as its able to re-fill after flushes carraied out already. I cut the 28mm Flow pipe that connects Boiler Flow to the Cylinder and flushed the coil. Trouble is Boiler...
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    Gravity Hot Water circulation

    Hi I have an old Gravity based open vent hot water system. Boiler on ground level. Boiler fires but hot water does not reach indirect cylinder upstairs. have tried flushing system few times but no joy. is there any tricks to help the initial flow of hot water? Thanks
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