Gas Boiler has no pressure

Discussion in 'Home energy' started by Mahons, Oct 7, 2006.

  1. Mahons

    Mahons Frequent Poster

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    163
    Hi,

    Overnight our boiler has lost all pressure therefore not firing. We do have a supply in to the house as the hob is lighting ok. I bled the system last night as it's the first time we've turned on the system since last spring. Could that have anyhting to do with it.

    Regards,

    Mahons
     
  2. BillK

    BillK Frequent Poster

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    1,159
    Do you mean there is no water pressure? If you have a combination boiler the water pressure should, ideally be about 1 bar for the boiler to work effectively. If this is the case then you need to top up the system. If you don't know how to do this then you need to get the boiler looked at by a professional; if the lack of pressure is on the gas side, then you need to get the boiler looked at by a professional.

    It is no job for an amateur as mistakes on your part could be lethal!
     
  3. nai

    nai Frequent Poster

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    650
    if it's a new house you probably have a valve for re-pressuring the system from the mains just under the boiler with - prob just has a screw to turn (not handle) just turn it and watch the pressure guage climb until about 1.5 bar (do this when cold!)
     
  4. Mahons

    Mahons Frequent Poster

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    163
    From what your saying BillK it sounds like the water level is low, what could have caused this over night

    Not really sure how to refilll it so best to get someone int to look at it. Thanks for your help

    Mahons
     
  5. mich

    mich Guest

    i had a similar problem last year. it was due to a blown circuit board. Hope thats not the answer as it was pricey to fix
     
  6. Mahons

    Mahons Frequent Poster

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    163
    hopefully not, the system is only 10 months old

    Mahons
     
  7. Mahons

    Mahons Frequent Poster

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    163
    nai you're a genius, eventually found the valve in the hotpress and straight away the pressure went up and the boiler kicked in.

    The wife says thanks!

    Any idea why the pressure would disappear like that...
     
  8. dillons

    dillons Frequent Poster

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    117
    Used to happen to me in my last place during the winter. Had Bord Gais engineer out & he said it was just one of those things that can happen in cold weather with freezing... I never really believed it but learnt how to fix it.

    I've since moved & had to bleed the rads... that caused a drop in pressure to zero so I had to turn the tap in the hotpress until it rose to 1.
     
  9. fobs

    fobs Frequent Poster

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    I have the exact same problem so going to try out your solution this evening!
     
  10. col

    col Frequent Poster

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    120
    I had the same problem last year and I had to top up several times before the pressure stableized at 1.5 bar. This year I only had to top it once after the summer shutdown.
     
  11. 3ps

    3ps Registered User

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    32
    I have the same and always suspected it was due to a small leak.
     
  12. Carpenter

    Carpenter Frequent Poster

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    I've always been puzzled myself about the pressure drop and inquiries with a heating installer yielded nothing more than "it's just one of those things". I imagine some water is lost from a system over time through evaporation and some of the plastics used in plumbing installations are not 100% vapour proof, leading to losses over time. Every joint, union and valve is a potential exit point for minute quantities of water also, especially through less than effective gland seals and the like. I think it's normal to expect to have to top up a system once or twice in a year, especially after a system has been shut down for some time.
     
  13. dillons

    dillons Frequent Poster

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    I agree carpenter but my experience last year in the apt I then owned was around 3 times a week during any cold spells!!
    the Bord Gais appointed service engineer couldn't find anything wrong or any leaks & put it down to cold weather & 'one of those things'!
     
  14. fobs

    fobs Frequent Poster

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    617
    Worked a treat!

    Our boiler was working agian last night after letting more water into the system. It was most likely due to bleeding all the radiators a few evenigs before but worked a treat so thanks for advice.
     
  15. Holy Well

    Holy Well Registered User

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    20
    I turned the valve on my Boiler last night, and it went from 0.2 to 1.5, but within about 2 hours it went back down to 1.

    It remained at 1 overnight.

    Any suggestions?
     
  16. Welfarite

    Welfarite Frequent Poster

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    From a previous post above, 1 bar sounds about right.
     
  17. marty004

    marty004 Frequent Poster

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    Hi,
    Just noticing this post. Our boiler has a label on it saying that normal pressure should be between 1 and 2.
    It also says that if below 0.3 you should contact someone.
    Ours constantly remains at 0.4 ->0.5 and has NEVER been at normal pressure since we moved into the new house (2 years ago). We only noticed this when it started making strange squeeling noises and having problems with our water pressure so we immediately got someone out to look at it.
    We were told it was fine.
    It doesn't seem fine to me when you hear the noise and you're having a shower and the water stops coming out. :eek:
    Is the boiler guy correct in saying it is ok and if so why if the pressure isn't in the normal range? Or should I get someone else out to fix the pressure?
     
  18. slan98

    slan98 Guest

    Hi

    Having same problem in new apt with boiler, pressure is at 0, can anyone let me know exactly where this valve is or what it looks like....ta!
     
  19. gianni

    gianni Frequent Poster

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    543
    Our valve is in the hot press on one of the pipes leading into the water tank. It is a small black 'tap' that looks more like a switch than a tap. It doesn't turn in a circle but rather 90 degrees to open and 90 degrees to close. Dunno if our setup is common or not so I'd advise caution before fiddling with taps/valves in your hotpress!
     
  20. pat127

    pat127 Frequent Poster

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    385
    Does anyone know what a 'semi-sealed' system is? That's what I was told I have since I switched to gas.The tap in the hot-press is permanently open and the pressure remains steady at 1 bar. I've had absolutely no problems except to bleed the system - the first rad in particular - every few months.