Announcement

Announcement Module
Collapse
No announcement yet.

Can't find very slow leak. Help!

Page Title Module
Move Remove Collapse
X
Conversation Detail Module
Collapse
  • Filter
  • Time
  • Show
Clear All
new posts

  • Can't find very slow leak. Help!

    I'm in the (hopefully) final stages of a frozen pipe fiasco in my own home. Three weeks ago the hydronic heater tripped out while it was -20 and froze everything. The heater supplies DHW and heat for the detatched garage and the apartment above it. To date I have replaced 3 sections of baseboard fin tube in the apartment, a shower valve, a washing machine valve and no less than 12 pieces of 3/4" copper pipe and fittings, mostly located in the space between the garage ceiling and the apartment. I have cut 17 holes in the ceiling and walls to find and fix these blown parts. I have inserted a shutoff valve half way through the heating loop (to dived the problem into 2 sections) and installed air pressure test ports at each end of the loop. Yesterday I finally got to the point where both sides of the loop will hold 40# of air pressure but only for a short time. If I leave 40 PSI of pressure in the system it will bleed off overnight. So, there is clearly a very slow leak somewhere. Hopefully the leak will be located where I have already cut an access port in the drywall; it's probably in one of my sweat joints. Other than the soapy water trick, does anyone have any bright ideas on how to locate this leak? What's the best ratio of detergent to water?

    TIA,
    Wayne in AK
    Last edited by wayneskid; 02-02-2009, 03:43 PM. Reason: added comment

  • #2
    Re: Can't find very slow leak. Help!

    try pressurizing the system up to 75-100 psi. you might be able to hear the leak.

    a tbsp soap/cup of water will probably be a good mixture for the soap test.

    Vince

    Comment


    • #3
      Re: Can't find very slow leak. Help!

      Originally posted by Vince the Plumber View Post
      try pressurizing the system up to 75-100 psi. you might be able to hear the leak.

      a tbsp soap/cup of water will probably be a good mixture for the soap test.

      Vince
      Vince, Thanks! I'm 68 years old and half deaf but I'll try the increased pressure idea. Since I posted this I already found one sweat joint that was leaking VERY slowly.

      Comment


      • #4
        Re: Can't find very slow leak. Help!

        With 70 PSI in the system I can't hear a thing; no surprise. I'll see if I can get a younger non-hearing impaired buddy over to have a listen. I fixed the one slow leak I found and it still looses pressure VERY slowly. I need a really brilliant idea; anyone?

        Comment


        • #5
          Re: Can't find very slow leak. Help!

          How do you have the pressure gauge connected sometimes it'll leak real slow at the gauge.

          Comment


          • #6
            Re: Can't find very slow leak. Help!

            Thanks CJ! I've checked all the fittings on my test gauge setup with soapy water and unless it's an internal leak in the gauge itself, my test fixture isn't the source of the problem. I guess I could test for a leaky gauge just to make sure. In the meantime I have located a simple stethoscope and am about to try that. But keep the ideas coming folks.

            Comment


            • #7
              Re: Can't find very slow leak. Help!

              pump it up more maybe to 125#... is it going all the way flat over night? air isnt an inert gas so the pressure will change with temperature

              Comment


              • #8
                Re: Can't find very slow leak. Help!

                do a full pressure water test.

                just kidding.

                keep plugging away, you'll find it.

                Vince

                maybe one of those mechanics stethoscopes might work to, the kind with the pointed probe

                Comment


                • #9
                  Re: Can't find very slow leak. Help!

                  Problem solved! The final leak (a very small one in one of my sweat joints) was found using a stethoscope. I listened to every joint until I found it. There was no sound at all until I put the stethoscope directly on the joint. Even 1 foot away from the joint, there was no sound.

                  The heat system is up and running now! Thanks to everyone for the help and encouragement.

                  Wayne in AK

                  Comment

                  Working...
                  X