Page 1 of 4 1234 LastLast
Results 1 to 13 of 43
  1. #1
    Join Date
    Apr 2010
    Posts
    94

    I cannot FIND THIS LEAK!!!!

    Unit - WIF. Refrigerant - 404A. Remote condenser through the roof. Your typical setup.

    This thing is losing 10lbs every other frikkin day. It takes 20. This %^**&%# leak should be blowing my hat off, yet I have been back on this thing with several other techs.

    Dye. Electronic leak detector. Nitrogen to 200#, which holds. Evacuation to 600 microns, which holds. We've pulled off every stitch of insulation and traced every inch of piping. At one point three of us were on site - one on the roof, one under the ceiling, one in the evap.

    There is no pressure relief. I've thought the leak may be coming from the high pressure control - thinking once it hits a certain pressure, it blows the charge, then resets, but we've blocked the coil and ran the head right at the tripping point and nothing.

    I'm convinced someone is sneaking in there and blowing off the charge.
    Last edited by Dad; 07-25-2011 at 06:59 PM. Reason: removed cussing

  2. #2
    Join Date
    Feb 2010
    Location
    Ontario Canada
    Posts
    1,341
    Could be a hot leak. System is good when everything is cold when the condenser heats up a pinhole starts leaking. Closes when everything cools down.
    just a thought.
    Never give up; Never surrender!

  3. #3
    Join Date
    Jul 2002
    Location
    NY
    Posts
    1,886
    Quote Originally Posted by trouble time View Post
    Could be a hot leak. System is good when everything is cold when the condenser heats up a pinhole starts leaking. Closes when everything cools down.
    just a thought.
    Yep just had one like that.
    Not what it use to be

  4. #4
    Join Date
    May 2004
    Posts
    11,985

  5. #5
    Join Date
    Dec 2008
    Posts
    113
    I had a leak not to long ago that would leak under vacuum but not under pressure, drove me out of my mind. Finally got lucky and the sob leaked a very small amount under pressure on the fourth attempt at a mechanical, gasketed, connection for the return oil line.

  6. #6
    Join Date
    Aug 2007
    Location
    Winter Haven, FL
    Posts
    4,355
    Next time it leaks out, which I guess is tomorrow...hit it with nitrogen, jack that pressure right up design max. Bring an ultrasonic detector too.

  7. #7
    Join Date
    Jun 2005
    Location
    Winston-Salem NC
    Posts
    1,133
    Quote Originally Posted by Joe Harper View Post
    Next time it leaks out, which I guess is tomorrow...hit it with nitrogen, jack that pressure right up design max. Bring an ultrasonic detector too.
    Isolate each component also.
    Evap, lines, compressor and I am assume it has a receiver, it too if you can.

  8. #8
    Join Date
    Jul 2003
    Location
    Massachusetts
    Posts
    288
    walk-in freezer? what method of defrost? if it's hot gas, that may be your answer.

  9. #9
    Join Date
    Feb 2006
    Location
    USA
    Posts
    4,381
    OP, I think its time to jack her up to 350# ...

  10. #10
    Join Date
    Jun 2005
    Posts
    171
    Quote Originally Posted by Kevin_1963 View Post
    Unit - WIF. Refrigerant - 404A. Remote condenser through the roof. Your typical setup.

    This thing is losing 10lbs every other frikkin day. It takes 20. This %^**&%# leak should be blowing my hat off, yet I have been back on this thing with several other techs. .
    That sounds a big leak loosing 1/2 the charge in a day


    Quote Originally Posted by Kevin_1963 View Post
    Dye. Electronic leak detector. Nitrogen to 200#, which holds. Evacuation to 600 microns, which holds. We've pulled off every stitch of insulation and traced every inch of piping. At one point three of us were on site - one on the roof, one under the ceiling, one in the evap.

    There is no pressure relief.
    And it holds? And no dye present anywhere? Don't know what to suggest but I'll be watching the post to learn something
    If we evolve from the monkey then why are there still monkeys.

    GOD Bless America.

  11. #11
    Join Date
    Mar 2011
    Location
    Edna Bay, Alaska Highest concentration of black bears in the US
    Posts
    623
    Maybe your competition messing with you.

  12. #12
    Join Date
    Sep 2008
    Location
    Western PA
    Posts
    25,540
    You need a good milk crate.

    Next time, pressure it up and SIT on that crate for a while.

    SIT a little longer.


    And then SIT some more.

    If that holds, then blow the nitrogen and pull your vacuum and go back to you milk crate and SIT.

    And SIT.


    Getting the picture here?


    Once you're pressure test and evacuation hold (doubtful, really, with a leak of this magnitude). Go ahead and gas it up and go back to getting a case of "waffle-butt"

    And sit...

    Check for leaks every 10 minutes with a good electronic. For cases like this, I like an H-10.


    FWIW, I have yet to see one of these magical temperature or pressure sensitive leaks. I've seen leaks get bigger with pressure or temperature, but none that stop and start.

  13. #13
    Join Date
    Jun 2005
    Location
    Winston-Salem NC
    Posts
    1,133
    I have seen ghost leaks, checking a new line set and coil hooked to a new OD, using 200 pounds of pressure showed a leak. Showed it and we checked and checked and checked and checked.

    Until I thought about something, pulled the charge from the OD unit and then found out 200lbs psig nitrogen was bleeding back through the service vales into the OD unit. Showing a "leak".

    I will, if I have a question about a leak, pressurize and go run call or grab lunch. And have gotten into the habit of isolating everything. If that means I have to unsweat the ID coil, oh well. I will find the leak, even if it costs me money. (I tend to get hyper-focused and determined at times).

Page 1 of 4 1234 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event