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Central Heating Pressure Dropping

2

Comments

  • #52
    K.Flyer
    Registered Users, Registered Users 2 Posts: 8,565 ✭✭✭K.Flyer


    John.G wrote: »
    I thought thats what I said..."If working properly, the air side pressure will read the precharge pressure when water side is at 0 bar and when water side pressure exceeds this (precharge pressure) then both pressures should read exactly the same." I didn't say anything about pumping up the air side, just to check it with water side pressure at 0 bar.

    Sorry, what I am trying to say is that the correct method to check the pre charge is with the wet side open. In other words, there should be nothing from the heating system and likewise pressurised water systems to interfere with the readings.


  • #53
    whizbang
    Registered Users, Registered Users 2 Posts: 1,953 ✭✭✭whizbang


    Is the Pressure gauge on a separate T off , or on a flow line ?
    Loosen it off to bleed any air from the Guage pipework.

    Maybe you have a sticky dicky pressure gauge.!!!


  • #54
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    whizbang wrote: »
    Is the Pressure gauge on a separate T off , or on a flow line ?
    Loosen it off to bleed any air from the Guage pipework.

    Maybe you have a sticky dicky pressure gauge.!!!
    I wish! Pic attached of the gauge, it's in-line with the loop tap. The regular daily situation now is that the pressure drops very slowly (takes all day) to about 0.2 bar. I open the loop tap, it takes about 5-10 seconds to rise to 1.0 bar. Then I run the heating for an hour, during which time the pressure rises to between 2.0 and 2.2 bar. Then once the heating switches off, the pressure drops back to 1.0 bar within an hour, then very slowly again the pattern repeats and it drops to around 0.2. Maybe it would hit zero if I left it, but we need the heating once a day!
    If it's a clue, the drop was much more dramatic when I first discovered it a few weeks ago, it would fall from 2.0 bar to zero in an hour or two.
    So whatever it is, it's improving. Still no sign of any visible leaks, but all other suggestions have been investigated except the pressure in the expansion tank (plumber isn't ringing back, he has the skills for complicated stuff!)


  • #55
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    tony glenn wrote: »
    I wish! Pic attached of the gauge, it's in-line with the loop tap. The regular daily situation now is that the pressure drops very slowly (takes all day) to about 0.2 bar. I open the loop tap, it takes about 5-10 seconds to rise to 1.0 bar. Then I run the heating for an hour, during which time the pressure rises to between 2.0 and 2.2 bar. Then once the heating switches off, the pressure drops back to 1.0 bar within an hour, then very slowly again the pattern repeats and it drops to around 0.2 Maybe it would hit zero if I left it, but we need the heating once a day!
    If it's a clue, the drop was much more dramatic when I first discovered it a few weeks ago, it would fall from 2.0 bar to zero in an hour or two.
    So whatever it is, it's improving. Still no sign of any visible leaks, but all other suggestions have been investigated except the pressure in the expansion tank (plumber isn't ringing back, he has the skills for complicated stuff!)

    Pic attached


  • #56
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    tony glenn wrote: »
    Pic attached

    Pic won't attach.


  • #57
    John.G
    Registered Users, Registered Users 2 Posts: 3,562 ✭✭✭John.G


    Tony, re suspect HW cylinder coil, IF the cylinder is vented then it will be fed from a CWST located in the attic which should provide ~ 0.2/0.25bar pressure head to the cylinder so if the coil is holed then the pressure gauge should never go below 0.2/0.25 bar and if a unvented cylinder then there is no way the pressure should go below 1.0 to 2.0 bar assuming in both cases that the "hole" will pass water both in and out so hopefully not the coil?.


  • #58
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    John.G wrote: »
    Tony, re suspect HW cylinder coil, IF the cylinder is vented then it will be fed from a CWST located in the attic which should provide ~ 0.2/0.25bar pressure head to the cylinder so if the coil is holed then the pressure gauge should never go below 0.2/0.25 bar and if a unvented cylinder then there is no way the pressure should go below 1.0 to 2.0 bar assuming in both cases that the "hole" will pass water both in and out so hopefully not the coil?.
    Thanks John. The gauge definitely showed absolute zero until the recent noticeable slow down in pressure drop, how do I tell if it's a vented or invented cylinder btw?


  • #59
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    tony glenn wrote: »
    Thanks John. The gauge definitely showed absolute zero until the recent noticeable slow down in pressure drop, how do I tell if it's a vented or invented cylinder btw?

    I've just checked the gauge, the heating has been off since six and the pressure dropped to 1.0 bar within an hour, it's now sitting at 1.0 bar since 7pm, maybe a 'hard to see' fraction below...in other words, a really slow drop. It's almost as if it's improving daily, but that's probably just wishful thinking. At least I'm losing weight climbing the stairs to the hot press fifty times a day to monitor the pressure!


  • #60
    Cantonahuges
    Registered Users Posts: 14 ✭Cantonahuges


    Did the pressure drop today


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  • #61
    John.G
    Registered Users, Registered Users 2 Posts: 3,562 ✭✭✭John.G


    tony glenn wrote: »
    Thanks John. The gauge definitely showed absolute zero until the recent noticeable slow down in pressure drop, how do I tell if it's a vented or invented cylinder btw?

    A vented cylinder will have a fairly large cold water storage tank in the attic.
    A unvented will generally have a pump located somewhere in the house and you will hear it cutting in/out there should also be another expansion vessel somewhere close to the hot water cylinder.
    There is just a faint possibility that mains water supplies the (unvented) hot water cylinder but it should still have a expansion vessel.


  • #62
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    Cantonahuges wrote: »
    Did the pressure drop today

    We might have the answer, a little too soon to tell. Turned off the immersion cylinder gate tap, then totally drained all hot water from the cylinder. Then opened the loop tap (pressure had indeed dropped to almost zero) and set pressure at 1.0. Ran the heating for an hour, pressure rose to 2.0 bar, checked the hot taps after the hour, water still cold. Left the cylinder closed, pressure then very slowly dropped to 1.0 bar, and seemed to stay there. Heating back on for an hour this evening, same story. If the gauge still shows 1.0 bar tomorrow morning, as s the cylinder is still isolated, we're thinking it must be a hole in the cylinder coil. Fingers crossed....


  • #63
    Cantonahuges
    Registered Users Posts: 14 ✭Cantonahuges


    Did you fine your problem I'm in the same situation a week before xmas all I need . My plumber telling me it's the boiler in the hot press but it's only 5 or 6 years old . I don't know can you trust any plumber to be honest maybe that's a bit harsh but can you see where I'm coming from


  • #64
    Cantonahuges
    Registered Users Posts: 14 ✭Cantonahuges


    tony glenn wrote: »
    We might have the answer, a little too soon to tell. Turned off the immersion cylinder gate tap, then totally drained all hot water from the cylinder. Then opened the loop tap (pressure had indeed dropped to almost zero) and set pressure at 1.0. Ran the heating for an hour, pressure rose to 2.0 bar, checked the hot taps after the hour, water still cold. Left the cylinder closed, pressure then very slowly dropped to 1.0 bar, and seemed to stay there. Heating back on for an hour this evening, same story. If the gauge still shows 1.0 bar tomorrow morning, as s the cylinder is still isolated, we're thinking it must be a hole in the cylinder coil. Fingers crossed....

    Did you fine the leak . I'm in the same situation all I need a week before xmas. My plumber is saying it's the boiler in the hot press not so sure if I can trust this guy maybe there all the same do you think your plumber is trustworthy or is it he does not know the answer. My problem is where will I get another plumber before xmas


  • #65
    Wearb
    Moderators, Home & Garden Moderators Posts: 6,305 Mod ✭✭✭✭Wearb


    Cantonahuges wrote: »
    Did you fine the leak . I'm in the same situation all I need a week before xmas. My plumber is saying it's the boiler in the hot press not so sure if I can trust this guy maybe there all the same do you think your plumber is trustworthy or is it he does not know the answer. My problem is where will I get another plumber before xmas

    Perhaps labeling them all as untrustworthy isn't the best start.

    Please follow site and charter rules. "Resistance is futile"



  • #66
    Cantonahuges
    Registered Users Posts: 14 ✭Cantonahuges


    Wearb wrote: »
    Perhaps labeling them all as untrustworthy isn't the best start.

    That is true maybe just the guy I have or is it just very difficult to fine a leak


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  • #67
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    Cantonahuges wrote: »
    That is true maybe just the guy I have or is it just very difficult to fine a leak

    My plumber is first class, he's given a lot of time and thought into trying to sort this...and it looks like the answer is a leak in the coil inside the immersion cylinder. With the gate valve off, and the gauge at 1.0 bar, I've run the heating twice, and each time now the pressure has dropped back to 1.0 bar.....and stayed there! I'll keep checking over the weekend, but I'm fairly sure that the he's found the answer....but many thanks to all involved for all the advice and suggestions over the last six (!) pages.


  • #68
    John.G
    Registered Users, Registered Users 2 Posts: 3,562 ✭✭✭John.G


    Sorry Tony but what is the gate valves purpose?


  • #69
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    John.G wrote: »
    Sorry Tony but what is the gate valves purpose?

    Might have the wrong name for it, it's the stop valve at the base of the cylinder that interrupts the flow of boiler heated water through the coil
    (I think I've got that right) Now the cylinder water stays cold when the heating is on, and the pressure holds at 1.0 bar afterwards.


  • #70
    John.G
    Registered Users, Registered Users 2 Posts: 3,562 ✭✭✭John.G


    Thanks, could be so that the coil "split" or whatever only opens up/leaks when hot or else you have a zone (motorized valve) at the other end to isolate the coil at both ends.


  • #71
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    John.G wrote: »
    Thanks, could be so that the coil "split" or whatever only opens up/leaks when hot or else you have a zone (motorized valve) at the other end to isolate the coil at both ends.

    Spot on, John. We've decided to leave any replacement work until after Christmas, and use the electric option on the immersion until then. I'm leaving the valve shut, also I've been told to zero the orange thermostat at the base of the cylinder, the motorized valve was mentioned, so you've just helped me understand the reason for that instruction!


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  • #72
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    tony glenn wrote: »
    Spot on, John. We've decided to leave any replacement work until after Christmas, and use the electric option on the immersion until then. I'm leaving the valve shut, also I've been told to zero the orange thermostat at the base of the cylinder, the motorized valve was mentioned, so you've just helped me understand the reason for that instruction!

    Well, having held off any further action until after the Christmas break, we're now ready to tackle the continuing pressure drop saga.
    Our trusty plumber is convinced it's a leaking coil inside the cylinder, after exhaustive investigations. I wish there was a 100% way to test that theory.... it's an expensive gamble if it's not the answer.
    My amateur test procedure has been:
    1) Raise pressure to 1 bar at bedtime with tap at base of cylinder closed. (heating off) Pressure zero next morning, open pressure lever and it takes only two or three seconds to raise pressure back to one bar.
    2) Same procedure, but with tap at cylinder base open, same pressure, same drop in morning, but now takes at least five seconds before gauge needle starts to move, and a couple of seconds more to hit one bar.
    So, I'm assuming more water is lost overnight when the CH water is allowed to run through the coil in the cylinder..so the coil must be split?
    Further comments welcome!


  • #73
    John.G
    Registered Users, Registered Users 2 Posts: 3,562 ✭✭✭John.G


    If the valve at the base of the cylinder is closed (and not passing) and motorized zone valve is closed (no demand for hot water) and not passing then you might assume that the coil is isolated but 1) above seems to say that you are still getting a pressure drop so you still really don't know where you are (as one of the valves may be passing).

    There is really only one course of action IMO and that is to blank, ie cap off both ends of the coil to take it completely out of the equation, it shouldn't take your plumber long to do this.
    Then run the CH system only and see what happens. That is the 100% way "to test that theory".


  • #74
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    John.G wrote: »
    If the valve at the base of the cylinder is closed (and not passing) and motorized zone valve is closed (no demand for hot water) and not passing then you might assume that the coil is isolated but 1) above seems to say that you are still getting a pressure drop so you still really don't know where you are (as one of the valves may be passing).
    There is really only one course of action IMO and that is to blank, ie cap off both ends of the coil to take it completely out of the equation, it shouldn't take your plumber long to do this.
    Then run the CH system only and see what happens. That is the 100% way "to test that theory".

    Thanks for your (continuing!) advice. The plumber originally suggested the two valve idea, but when I mentioned it to him in our last conversation, he now feels that by the time he drains and refills the system etc to do that, to reduce potential expense it might be better to take a chance and change the cylinder at the same time. Bear in mind that there is absolutely no visible sign of any leakage upstairs or downstairs after two months now, so the 12 year old cylinder is a very strong contender. (Nine-month old boiler, modern plumbing throughout, all connections and most 'plastic' pipework
    visible)


  • #75
    John.G
    Registered Users, Registered Users 2 Posts: 3,562 ✭✭✭John.G


    Obviously the decision is yours but another far less time consuming method is to heat up the cylinder either with the electric immersion or with the coil, then ensure both coil valves closed and break a compression fitting either at the coil inlet or outlet (which ever is the easiest) and see if water continues to leak from the coil. Do you know where the zone valve is located in relation to the coil inlet?.


  • #76
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    John.G wrote: »
    Obviously the decision is yours but another far less time consuming method is to heat up the cylinder either with the electric immersion or with the coil, then ensure both coil valves closed and break a compression fitting either at the coil inlet or outlet (which ever is the easiest) and see if water continues to leak from the coil. Do you know where the zone valve is located in relation to the coil inlet?.
    John, I've attached pics of the


  • #77
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    tony glenn wrote: »
    John, I've attached pics of the

    John, I've attached pics of the general area, the expansion vessel is temporarily supported as I removed it's shelf ready for the job.
    How about if I ran all hot taps until cold, then switched on the heating for a couple of hours with the coil tap closed. Then, if the hot taps run warm (or even hot) that would suggest a coil leak? (A little knowledge is a dangerous thing lol)


  • #78
    John.G
    Registered Users, Registered Users 2 Posts: 3,562 ✭✭✭John.G


    The E.vessel seems to be connected into the system between the zone valve and the coil inlet??, now, if so, and with the zone v/v and the balancing valve closed the E.vessel is effectively isolated from the system which is the same as having no E.vessel under these conditions, with the balancing valve opened/partially opened then the E.vessel is connected to the system but is certainly not the correct way of doing so if I am interpreting your pics correctly. Can you see if it is connected as I think it is.??


  • #79
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    John.G wrote: »
    The E.vessel seems to be connected into the system between the zone valve and the coil inlet??, now, if so, and with the zone v/v and the balancing valve closed the E.vessel is effectively isolated from the system which is the same as having no E.vessel under these conditions, with the balancing valve opened/partially opened then the E.vessel is connected to the system but is certainly not the correct way of doing so if I am interpreting your pics correctly. Can you see if it is connected as I think it is.??
    Do these further pics help?


  • #80
    John.G
    Registered Users, Registered Users 2 Posts: 3,562 ✭✭✭John.G


    Can you look at or take another pic to confirm/or not that the highlighted pipe is directly connected from the zone vale (also highlighted) to the coil inlet ie no other pipe connected in (apart from the E.vessel T) between the zone valve and the coil inlet.


  • #81
    John.G
    Registered Users, Registered Users 2 Posts: 3,562 ✭✭✭John.G


    John.G wrote: »
    Can you look at or take another pic to confirm/or not that the highlighted pipe is directly connected from the zone vale (also highlighted) to the coil inlet ie no other pipe connected in (apart from the E.vessel T) between the zone valve and the coil inlet.

    TEMP2 shows the path a bit clearer, just confirm no other pipes branching off as requested abve.


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  • #82
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    John.G wrote: »
    Can you look at or take another pic to confirm/or not that the highlighted pipe is directly connected from the zone vale (also highlighted) to the coil inlet ie no other pipe connected in (apart from the E.vessel T) between the zone valve and the coil inlet.
    Any good? Access limited when I'm trying to hold the phone at the same time!


  • #83
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    tony glenn wrote: »
    Any good? Access limited when I'm trying to hold the phone at the same time!

    I'll try again...


  • #84
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    tony glenn wrote: »
    Any good? Access limited when I'm trying to hold the phone at the same time!
    Again


  • #85
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    tony glenn wrote: »
    Any good? Access limited when I'm trying to hold the phone at the same time!

    Now saying file too large.


  • #86
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    tony glenn wrote: »
    Now saying file too large.

    Pics


  • #87
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    Pic


  • #88
    John.G
    Registered Users, Registered Users 2 Posts: 3,562 ✭✭✭John.G


    Just use my Temp1 and Temp2 as a guide and simply just look and see if the pipework is as I think it is.


  • #89
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    Pic


  • #90
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    John.G wrote: »
    Just use my Temp1 and Temp2 as a guide and simply just look and see if the pipework is as I think it is.

    Ok, vertical pipe from zone valve travels up to brass safety valve, but before that branches off to upper inlet of hot water cylinder, whilst also connecting to back of e vessel on the way.
    Weird that pics suddenly won't send btw.


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  • #91
    John.G
    Registered Users, Registered Users 2 Posts: 3,562 ✭✭✭John.G


    tony glenn wrote: »
    Ok, vertical pipe from zone valve travels up to brass safety valve, but before that branches off to upper inlet of hot water cylinder, whilst also connecting to back of e vessel on the way.
    Weird that pics suddenly won't send btw.

    Thanks Tony, That confirms that if the HW zone valve is shut and the balancing valve is shut then IMO you have no expansion path which will lead to the boiler PRV (safety valve) lifting. Having said that and even though incorrectly installed there should be a expansion path through the coil and (if open) the opened balancing valve. For the moment open this balancing valve fully and leave so.
    The "brass safety valve" is actually a AAV (automatic air vent), again this should have been installed upstream of the zone valve, you can just check for any air by opening (if shut) a little cap on top of this AAV nozzle to release any entrapped air and then re closing it.
    Are you reading the pressure off the pressure gauge to the right of this ballancing valve and is the highlighted valve left in the open position permanently?


  • #92
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    John.G wrote: »
    Thanks Tony, That confirms that if the HW zone valve is shut and the balancing valve is shut then IMO you have no expansion path which will lead to the boiler PRV (safety valve) lifting. Having said that and even though incorrectly installed there should be a expansion path through the coil and (if open) the opened balancing valve. For the moment open this balancing valve fully and leave so.
    The "brass safety valve" is actually a AAV (automatic air vent), again this should have been installed upstream of the zone valve, you can just check for any air by opening (if shut) a little cap on top of this AAV nozzle to release any entrapped air and then re closing it.
    Are you reading the pressure off the pressure gauge to the right of this ballancing valve and is the highlighted valve left in the open position permanently?
    In fairness, that AAV must have been there from original build, it has paint splashes on it from first painting


  • #93
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    John.G wrote: »
    Thanks Tony, That confirms that if the HW zone valve is shut and the balancing valve is shut then IMO you have no expansion path which will lead to the boiler PRV (safety valve) lifting. Having said that and even though incorrectly installed there should be a expansion path through the coil and (if open) the opened balancing valve. For the moment open this balancing valve fully and leave so.
    The "brass safety valve" is actually a AAV (automatic air vent), again this should have been installed upstream of the zone valve, you can just check for any air by opening (if shut) a little cap on top of this AAV nozzle to release any entrapped air and then re closing it.
    Are you reading the pressure off the pressure gauge to the right of this ballancing valve and is the highlighted valve left in the open position permanently?
    In fairness, that AAV must have been there from original build, it has paint splashes on it from first house painting. The highlighted valve is in the open position, and yes that's the gauge I read from. If it's any clue, this pressure drop only began sometine since the new boiler was fitted. It was ok at the end of last season (March 19) when first used, but started this season (October 19)


  • #94
    John.G
    Registered Users, Registered Users 2 Posts: 3,562 ✭✭✭John.G


    As I said, then assuming that the balancing valve was open/partially opened all the then there was/is a expansion path.
    I assume the zoning was done with the new boiler install.


    Can't really offer any more at the moment except for now keep that valve full open and take another series of tests with this valve opened at all times., must remember that when you were doing tests with both valves closed that even loosing a eggcup full of water from the system would result in a almost instant pressure drop and when re pressurising a few seconds should have been enough.

    Your plumber may have some perfectly logical reason for this set up, maybe your new boiler has a integral E.vessel.


  • #95
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    John.G wrote: »
    As I said, then assuming that the balancing valve was open/partially opened all the then there was/is a expansion path.
    I assume the zoning was done with the new boiler install.


    Can't really offer any more at the moment except for now keep that valve full open and take another series of tests with this valve opened at all times., must remember that when you were doing tests with both valves closed that even loosing a eggcup full of water from the system would result in a almost instant pressure drop and when re pressurising a few seconds should have been enough.

    Your plumber may have some perfectly logical reason for this set up, maybe your new boiler has a integral E.vessel.

    That's a new e vessel he fitted at the time.
    Anyway John, thanks for all your help, especially on a Saturday (time and a half?) I'll follow your valve advice.
    If you don't mind, I'll let you know the final outcome...just so you can sleep at night once more! Regards Tony


  • #96
    John.G
    Registered Users, Registered Users 2 Posts: 3,562 ✭✭✭John.G


    Yes please, keep us all informed as it may help someone else sometime apart from being very interesting.


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  • #97
    John.G
    Registered Users, Registered Users 2 Posts: 3,562 ✭✭✭John.G


    Should also have suggested that you re pressurize to 1.3/1.5 bar when cold because if the initial pressure is 1.0 bar then the slightest loss of water or any entrained air bubble collapse will result in sudden loss of pressure.

    I keep re thinking that if you have/had a holed coil that the pressure should still read ~ 0.2 bar or so.


  • #98
    John.G
    Registered Users, Registered Users 2 Posts: 3,562 ✭✭✭John.G


    tony glenn wrote: »
    That's a new e vessel he fitted at the time.
    Anyway John, thanks for all your help, especially on a Saturday (time and a half?) I'll follow your valve advice.
    If you don't mind, I'll let you know the final outcome...just so you can sleep at night once more! Regards Tony

    Tony,
    I think I may have earned that time and a half.
    If you look at this link which is your second pic in your post #79 you will see a NR valve in the coil outlet after the balancing valve which allows water to flow from the coil but not back through it to the E.vessel even when its fully opened, so the only time that the system can expand into the E.vessel is when the HW zone valve is opened, at all other times you have effectively no E.vessel in your system.
    https://www.boards.ie/vbulletin/attachment.php?attachmentid=500996&d=1579956933


  • #99
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    John.G wrote: »
    Tony,
    I think I may have earned that time and a half.
    If you look at this link which is your second pic in your post #79 you will see a NR valve in the coil outlet after the balancing valve which allows water to flow from the coil but not back through it to the E.vessel even when its fully opened, so the only time that the system can expand into the E.vessel is when the HW zone valve is opened, at all other times you have effectively no E.vessel in your system.
    https://www.boards.ie/vbulletin/attachment.php?attachmentid=500996&d=1579956933

    Well, here's today's situation, I have to hurry as the men in white coats are on the way.
    We had the cylinder replaced this week as it was agreed that it was probably the solution.
    Sure enough, the first couple of days were ok, a fractional pressure drop after each heating session, but I assumed that were air pockets here and there after the major disturbance, I bled all the rads in case. All seemed well for a day or two, definitely only a fractional overnight pressure drop.
    Yesterday, after a half-hour heating we went out for the day and returned to almost zero pressure again. Topped up to 1.0 bar and left (no heating) overnight, zero this morning. Took it up to 2.0 at 9.30, it was almost zero within two hours, way worse than it's ever been.
    BUT here's what's different this time....it takes literally only two or three seconds max from opening the lever to raise from zero to 2.0 bar, in other words hardly any water input.
    Still absolutely no signs of leakage, checked the new boiler and all rads. Any thoughts?

    Left a message with the plumber, heading for wits end scenario shortly.


  • #100
    John.G
    Registered Users, Registered Users 2 Posts: 3,562 ✭✭✭John.G


    tony glenn wrote: »
    Well, here's today's situation, I have to hurry as the men in white coats are on the way.
    We had the cylinder replaced this week as it was agreed that it was probably the solution.
    Sure enough, the first couple of days were ok, a fractional pressure drop after each heating session, but I assumed that were air pockets here and there after the major disturbance, I bled all the rads in case. All seemed well for a day or two, definitely only a fractional overnight pressure drop.
    Yesterday, after a half-hour heating we went out for the day and returned to almost zero pressure again. Topped up to 1.0 bar and left (no heating) overnight, zero this morning. Took it up to 2.0 at 9.30, it was almost zero within two hours, way worse than it's ever been.
    BUT here's what's different this time....it takes literally only two or three seconds max from opening the lever to raise from zero to 2.0 bar, in other words hardly any water input.
    Still absolutely no signs of leakage, checked the new boiler and all rads. Any thoughts?

    Left a message with the plumber, heading for wits end scenario shortly.

    Have only my steam driven IPhone 4 just now but will endeavour to give a more detailed answer when I get home tonight, you should be able to read the EV capacity in litres on the label now exposed by the missing support, you mi
    Might post it if you can see it. Also do you know what the initial pre pressure was/is??. It's possible that the diaphragm is jammed hard up against the water end, hence the the tiny amount of water required to pressurise (filling pressure).
    You might also confirm or otherwise that the EV is positioned as stated above, if so then it will only be effective if HW zone vale is permanently opened but maybe your plumber has clarified this.


  • #101
    tony glenn
    Registered Users Posts: 609 ✭✭✭tony glenn


    John.G wrote: »
    Have only my steam driven IPhone 4 just now but will endeavour to give a more detailed answer when I get home tonight, you should be able to read the EV capacity in litres on the label now exposed by the missing support, you mi
    Might post it if you can see it. Also do you know what the initial pre pressure was/is??. It's possible that the diaphragm is jammed hard up against the water end, hence the the tiny amount of water required to pressurise (filling pressure).
    You might also confirm or otherwise that the EV is positioned as stated above, if so then it will only be effective if HW zone vale is permanently opened but maybe your plumber has clarified this.
    Today's update.... dropping 0.3 bar cold in one hour. Still no sign of any leak or damp patch, and the puzzle remains i.e. it was almost ok for two days after the cylinder was changed.
    I did put up one shelf in the utility room during the Summer, (timber frame house, plasterboard internal walls) The screws were to the left of the rad below, is it possible that the plastic pipe runs at 45° behind the wall, (in which case I could have holed the pipe) or is it always vertical or horizontal?
    PS No markings of any sort on the EV cylinder btw.


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