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Dripping water at copper to plastic connection question

Pheraph
Pheraph Member Posts: 23
in Radiant Heating

Good evening,

In October or November I my house wasn't heating properly, followed the instructions from a previous post purged the air from the system and left it around 12 psi. Everything seemed to be working fine, but now I noticed a small drip coming from the system. Looking at the pressure, it seemed a bit high at 50 psi even though I left it around 12 psi when I initially purged the air. Is it normal for pressure to rise that high? I am concerned that is what might be causing the drip from the copper - plastic tube connections. What are your thoughts?

leak.jpg

My previous post here, which helped tremendously is below.

Thank you for your time!

https://forum.heatinghelp.com/discussion/195620/radiant-heating-pump-pulling-power-0-gpm-output-advice-appreciated

Comments

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 17,845

    pressure is to high. Your PRV valve that feeds water to the boiler could be leaking by or it could be the expansion tank. Pressure should be 12-15psi.

  • hot_rod
    hot_rod Member Posts: 25,123

    it looks like the leak may be in the sweat joint above the crimp ring

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    Mad Dog_2
  • mattmia2
    mattmia2 Member Posts: 12,835
    edited January 20

    see my comments about the expansion tank on that thread.

    er….I was thinking of another thread but most likely your expansion tank lost its precharge or is bad.

  • mattmia2
    mattmia2 Member Posts: 12,835
    edited January 20
  • Pheraph
    Pheraph Member Posts: 23
    edited January 20

    Ah, thanks. I should probably call someone out to fix that then. Don't want to risk messing something up. Unless it is relatively easy, are Expansion tanks easy to swap out?

  • Larry Weingarten
    Larry Weingarten Member Posts: 3,850

    Hi, It looks like Uponor PEX has been mixed up with a copper crimp ring. Shouldn't the fitting in the T be Uponor and the ring be the same as the other expansion rings used? A soldered fitting that didn't quite take, seems possible too.

    Yours, Larry

  • Pheraph
    Pheraph Member Posts: 23

    Is there a way for me to lower the pressure until I can get a contractor to come out? I am concerned there are potential leaks I cant see under the flooring.

  • hot_rod
    hot_rod Member Posts: 25,123
    https://forum.heatinghelp.com/discussion/comment/1836537#Comment_1836537

    I think all of the expansion pex brands now accept crimp rings as an option.

    When it is changed it could become an expansion adapter.

    Maybe it was done by someone that didn't own the expansion tool?

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Larry Weingarten
    Larry Weingarten Member Posts: 3,850

    Hi @hot_rod , Didn't it used to void the warranty if different systems were mixed up? Also, some of the insert fittings I've seen are a bit rough, looking like it would be easy for them to leak. And then there is the little flow restriction created … I know, nitpicky! 🤨

    Yours, Larry

  • hot_rod
    hot_rod Member Posts: 25,123

    Pexhouse does a great job of explaining the listing and spec numbers on tube.

    https://pexhouse.com/how-to-read-a-pex-pipe-print-stream/

    If the tube has F 876 or F876/F877, then by ASTM definition the various fittings that are tested and certified are listed. I don't know that legally a manufacturer can deny using other listed fittings or brands of fittings and rings? Some of the Manufacturers don't even make their own fittings and rings. They buy them from various sources.

    Same with radiant manifolds. Any pex with the correct standard listing can be used.

    If you dig deep enough in their tech literature I thing the tube manufacturers state that now.

    The internal bore issue is another discussion. On a hydronic loop you may only have two fittings, so no big deal.

    In a home plumbing system it is a different concern. Especially with plumbers that use a lot of ells with pex, as if it is copper tube :)

    Screenshot 2025-01-20 at 12.57.06 PM.png
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Pheraph
    Pheraph Member Posts: 23

    I am not sure about all of that, some company nearby installed it before I bought the condo. o.O Is there a way to lower the pressure manually until tomorrow? I have a contractor coming out.

    Thanks!

  • mattmia2
    mattmia2 Member Posts: 12,835

    Does the pressure go down if you turn the system off and let it cool?

  • Pheraph
    Pheraph Member Posts: 23

    I noticed the temp went down, pressure stayed around 40-50 psi

  • Pheraph
    Pheraph Member Posts: 23

    I connected a hose to the purge valve and opened that a little. gets the pressure down to 12, but once valve closes it just goes back up pretty fast.

  • mattmia2
    mattmia2 Member Posts: 12,835

    Does this boiler also heat domestic hot water or just heating. If it does DHW it could be the coil for the DHW leaking or the PRV isn't holding. If no DHW then it has to be the PRV leaking. Try turning off the manual valve to the prv.

  • Larry Weingarten
    Larry Weingarten Member Posts: 3,850

    Hi, There is probably a pressure reducing valve that supplies water to the system. It should have a shut-off valve with it. Can you give us some photos of this valve and surrounding piping?

    Yours, Larry

  • Pheraph
    Pheraph Member Posts: 23
    https://forum.heatinghelp.com/discussion/comment/1836582#Comment_1836582

    I turned the temperature down on the system, will see if that changes anything.

  • Pheraph
    Pheraph Member Posts: 23

    Nope, no change in pressure oddly.

  • Pheraph
    Pheraph Member Posts: 23

    Contractor came out, stated he thinks there is a hole in the heat exchange coil inside the tank. When I purge the pressure from the system, the pressure jumps back up again after closing the valve. He states the pressure is coming from the hole in the potable water tank. The water/heater was turned off, so the water has been cooled. They stated I will need a new tank, that the heating exchange coil cant be swapped out since it is welded.

  • mattmia2
    mattmia2 Member Posts: 12,835
    https://forum.heatinghelp.com/discussion/comment/1836619#Comment_1836619
  • mattmia2
    mattmia2 Member Posts: 12,835

    The test for the DHW heat eachanger leaking is to turn off the cold water to the domestic hot water and see if the pressure stops going up.

  • neilc
    neilc Member Posts: 3,026

    um,

    why isn't a Pressure Relief Safety Valve blowing off ?

    ( 40 - 50 psi )

    known to beat dead horses
  • Pheraph
    Pheraph Member Posts: 23

    There isnt one on this system I guess. :(

  • Pheraph
    Pheraph Member Posts: 23

    How complicated is it to swap out the combi tank? Had a few quotes come back with what feels like a crazy high price. If I were to get a new system, what would work best? Combi tank, combi boiler, tankless heaters? Trying to avoid spending a down payment on a house to get this swapped out. If it is easy enough to swap out the combi tank myself, I might just do that. Thoughts? I am avoiding putting the prices up since it was in the rules not to post it.

  • mattmia2
    mattmia2 Member Posts: 12,835

    is it an indirect tank type water heater or a heat exchanger inside a combination boiler or what?

  • Pheraph
    Pheraph Member Posts: 23

    I think heating exchanger inside combi boiler

  • mattmia2
    mattmia2 Member Posts: 12,835

    You'd probably have to get the heat exchanger from the boiler manufacturer. Probably a fair bit of disassembly to get to it but not too hard if you keep track of wat you took apart and put it back together the way you took it apart.

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