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tube is plugged

shawn_7 Member Posts: 4
i installed 300' of PEX in a garage and covered it with concrete. once it dried i discovered i could not get a flow through the tube. i plugged one end and pressurized the other at 200 psi for several hours with no pressure loss. i figure the tube must be plugged or kinked. is there a way to locate where the tube is plugged without tearing up several square feet of concrete?



  • Weezbo
    Weezbo Member Posts: 6,232
    try hot glycol..maybe it has ice in it.....*~/:)

    and break out waterbed mats and cover the floor with them and crank some BTU's to the slab....
  • shawn_7
    shawn_7 Member Posts: 4
    i don't think so

    it has been like this for a year i think it is kinked or maybe it was plugged while being formed.

  • Ed_26
    Ed_26 Member Posts: 284
    plugged pex?

    By your description, you have pressure tested the piping. Now when you had the pressure on, did you open either end to see if the (air?) came out? You should get flow both ways. What size of pipe? How did you lay it out? How is it secured in the slab?
    You could use a small. stiff wire & fish it down the pipe from either end to see if there is concrete in the risers (tails). Good luck!
  • Jeff Lawrence_24
    Jeff Lawrence_24 Member Posts: 593
    air test

    Before I put a pressure test on a pex job, I simply blow through the tube. That lets me know 2 things, first there is not a major kink in the tubing and second, I am not hooking up the tubing on the same side of the loop.

    I've never run into a plugged tube.


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  • shawn_7
    shawn_7 Member Posts: 4

    i did run a wire down both ends. on one end the wire went in 160' and on the ohter end the wire went in 110'. that still leaves 30' which is still alot of concrete to break up. i am just wondering if anyone has run into a problem like this before and had found a solution. thanks everyone for the your input on this.

  • hr
    hr Member Posts: 6,106
    That's going to be a tough one

    an air test, alone, will not show up a partially plugged or kinked tube. It is possible for a kink to occur during the pour, even though it looked fine before the pour. All it takes if for a concrete installer to snag a boot on a loop end and cause a kink.

    I've learned not to put a tie at the very end of a loop for this reason. Tie on either side of a loop to allow movement.

    I once watched a pex tube layout that I did on a warm sunny day. As the sun went down and the tube cooled off all the tube runs "tightened up" That is, as the tube contracted it pulled on the ties at the loop ends. All the tube runs got very tight and straight as the tube contractted from the extreme temperature change. That's when I learned about loop end tying.

    Of course PAP makes this a non issue :)

    One method would be to rent an IR camera and film the start up with a cold slab. I'll bet it would easily "see" that bottle neck :)

    hot rod

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  • Ted_9
    Ted_9 Member Posts: 1,718

    Thanks for another great tip hot rod.


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  • jerry scharf_3
    jerry scharf_3 Member Posts: 419
    if you're shoved a wire down it

    Someone had a great idea here of attaching a radia source to the end of the wire. Then you go around and follow the sound on a receiver over top of the slab to find the wire.

    If you've pushed both ends and have found a block, I'm afraid it's time to break out the jackhammer once you find exactly where it stops on one end. It doesn't really matter why, if you want it to work you have to open it up and fix it. If it were me, I would start from the shorter end, on the possibility that at some point it's drag that makes it so you can't feed the wire farther.

    It's hard to imagine that a kink could hold air pressure for a week, but I guess stranger things have happened. I guess it's murphy's law that something you want to flow has a perfect block and the fitting you want to be dry leaks. :(

    best of luck, jerry
  • shawn_7
    shawn_7 Member Posts: 4

    thanks everyone for your help on this, i think i am just going to break out the jack hammer to the place where it might be, probably at the end where i could only go 110'.

    thanks again,
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