Heating Problems

Discussion in 'Home energy' started by Dev104, Apr 24, 2009.

  1. Dev104

    Dev104 Registered User

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    10
    My heating is acting up and I don't know where to start.
    • Heating system: Baxi System 35/80 IE
    • Two water tanks in the attic.
    The pressure is constantly up and down from 0.2 to 0.5. It sounds like something that should be taking off at an airport and some (not all) radiators heat up.
    Does anyone know how to increase the pressure (if that will solve the jumping pressure). I do not have a connector pipe that I have read about in several posts to top up pressure and besides I cannot see anywhere that this connector pipe would connect too.
    I have found a number of screw valves in the hotpress, 2 coming down from the tanks in the attic and feeding to the hot tank (I think, hard to see) another 2 that feed away from the tank. One is slightly thinner than the other.
    There is also two (black) turn valves under the Baxi boiler one being boiler flow and the other being boiler return. I turned the boiler flow valve and the pressure shot up to 1.5 and then thought I needed to close the value and all would be okay, but the pressure returned to 0.2 and the jet engine started again.

    I'm going crossed eye'd from reading posts, so if anyone could direct me or know how to solve these problems I would be very greatful.

    Boiler information book from: http://www.partsarena.com/baxi/
     
  2. DavyJones

    DavyJones Frequent Poster

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    1,987
    How long have has boiler been installed?

    The system boiler should only be connected to a sealed system.

    Do you have a small tank and large tank in attic?
     
  3. Dev104

    Dev104 Registered User

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    10
    Boiler installed with new house build in early 2006. Had Bord Gais out when we moved in and they gave it the all clear. Also had them out mid last year to service the boiler and got the alll clear.
    I have two water tanks in the attic of equal size.
    Should I be worried ??????
     
  4. DavyJones

    DavyJones Frequent Poster

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    1,987
    No,

    Look at your cylinder. you will see four pipes that connect to it. One off the top and one that goes into the very bottom. At the opposite side of the bottom entering pipe, you should see two pipes that enter the cylinder about 18" apart and parallel.

    Of these two pipes does a smaller pipe run from the bottom one and up into attic?
     
  5. DGOBS

    DGOBS Frequent Poster

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    846
    Have often seen the back system boiler installed on open vented and semisealed systems (will run at .2 bar just) sounds like you may need a new heat exchanger and maybe an ideal to seal and pressurize the system
    Depending you may also require a chemical power flush if the system is badly scaled or sludged
     
  6. Dev104

    Dev104 Registered User

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    10
    There is a smaller (width) pipe that runs from the attic around the side of the hot tank and joins to a pipe that is vertical with what looks like a pressure release that you would see on an old pressure cooker our parents might have had. This pipe is cold to the point where the red screw valve joins it to the vertical pipe.

    I have tried to turn this and it turns about a quater turn and stops. When doing that I ran back to the boiler but pressure didn't increase and there was no large noisy gushing sound from the tank that have been mentioned in other posts.

    There is water in the tanks in the attic and water is coming from the taps and toilets, so I assume there is water flowing from the attic via those pipes.
     
  7. DavyJones

    DavyJones Frequent Poster

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    1,987
    Does that valve turn anymore depending on which way you turn it?

    If you bleed the rads upstairs does water come out of them?
     
  8. Dev104

    Dev104 Registered User

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    10
    Thanks DGOBS, do you think the system would be badly scaled or sludged in such a short space of time (3 years). The water is not hard in this area (so I've been told), but I also cannot confirm that the system was flushed after install and before moving in. I should have confirmed, but didn't. More fool me.
     
  9. Dev104

    Dev104 Registered User

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    10
    Thanks Davy for the replies.

    I didn't want to force the screw valve but it seems to stop at the qtr turn. This was in an anti-clockwise direction.
    Have bled all the rads and water is now coming out of all of them, one or two were airlocked and are now heating, but the others that weren't airlocked are not heating, just water coming out of the knob on the side when bled.
    Each rad thermo is up to max and the wall thermo is at about 22
     
  10. DavyJones

    DavyJones Frequent Poster

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    1,987
    does it screw atleast a few full rotation when you go clock wise?
     
  11. Dev104

    Dev104 Registered User

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    10
    No, same as. A qtr turn either way. Its currently closed (?) in a clockwise position and when I attempt to open it its only a qtr turn anti-clockwise.
    There is a second (thicker) pipe leading directly from the bottom side of the tank also has a red turn screw valve which gives a number of turns in both directions. Currently open, but I'm thinking this feeds hot water to the house ?
     
  12. DavyJones

    DavyJones Frequent Poster

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    1,987
    The valve is like the rest of the valves in hot press I.E red wheeled?

    Right, my money is on that valve being closed. Sometimes they stick and you may have to use a bit of muscle. you will not break it with your hand.
    As you have seen from the other valve it should move freely both ways. It is not fully open because if it was it would screw right back the other way.
     
  13. Dev104

    Dev104 Registered User

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    10
    Excellent, will give it a go. Assuming that is all I need to do ? Full turn, watch the pressure increase on needle in boiler and close again ?
     
  14. DavyJones

    DavyJones Frequent Poster

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    1,987
    nah, you have a semi sealed system, the pressure won't rise byond static head pressure.

    Confirm if valve is open or not and then we'll talk about changing system to a fully sealed one.
     
  15. Dev104

    Dev104 Registered User

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    10
    Davy, excellent work. I forced the red turn screw and the gushing sound and the needle shot up. I cannot beleive how simple the solution was and how much you have saved my pocket and ear ache from the good lady.

    Thank you so much for all your help. I will keep an eye on the other issues and hopefully the return of pressure will have a knock on affect and solve the cold rads also. Thanks again. Where do I send payment ?
     
  16. Dev104

    Dev104 Registered User

    Posts:
    10
    Sorry Davy, just spotted your last message. Do you think a fully sealed system would solve this problem in the long term. Boiler pressure is up about 1.2 now and the house is already starting to heat up.

    Is the fully sealed system a retro fit ? Could you suggest a rough guestimate of what this might cost me ?
     
  17. DavyJones

    DavyJones Frequent Poster

    Posts:
    1,987
    In my opinion, semi sealed systems are a crime to plumbing, and I am nearly sure they break water by-law in relation to risk (no matter how small) of cross contamination.

    Changing over is easy and could/should cost no more than €200. however your system will work fine now, as good as if it was fully sealed.


    your thanks is payment enough,
    but if over time you feel AAM is a helpful resource you can check out the yellow box at the very bottom of each page. ;)
     
  18. Dev104

    Dev104 Registered User

    Posts:
    10
    Consider it done. Thanks again for all your help and sticking with me.
     
  19. ciaran11

    ciaran11 New Member

    Posts:
    4
    Hi I have a similar heating problem:

    My heating is working but pressure almost down to 0.5..
    • Heating system: Baxi System 35/80 IE
    • One water tanks in the attic.

    Does anyone know how to increase the pressure (if that will solve the jumping pressure). I do not have a connector pipe that I have read about in several posts to top up pressure and besides I cannot see anywhere that this connector pipe would connect too.
    I have found a number of screw valves in the hotpress, 2 coming down from the tanks in the attic and feeding to the hot tank (I think, hard to see) another 2 that feed away from the tank. One is slightly thinner than the other.
    There is also two (black) turn valves under the Baxi boiler one being boiler flow and the other being boiler return.

    So it seems very similar to above posts with 4 pipes in the hotpress - picture attached.

    The valves on all these 4 pipes seem to be open - all turned left as far as possible.

    There is another value on the floor as in picture - but this seems to be neither open or closed - half way between both.

    I looked at the tank in the attic - it is just one full tank..

    I was at this for 1 hour and could not increase the pressure - any ideas ? Thanks
     
  20. Leo

    Leo Moderator

    Posts:
    8,182
    The lower valve in the hot press may be to balance flow between central heating and water tank. The one on the large pipe feeding the bottom of the tank is the feed into the immersion tank from the attic supply, the second one on the feed from the tank in the attic is likely feeding the cold taps. (Run the cold tap and close this valve to confirm.) One of the others is likely to top up the heating system.

    Can you check the pressure vessel? You'll need a pump with a schrader valve and a pressure gauge.

    Might be time to get a pro in who can run a full test and tune the system up.