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what is easiest way to loosen galvanized dielectric union?

Darrell_4 Member Posts: 77
Yes...but, make sure that you ignore the leak for at least six months so that the union is barely recognizable and allows lots of new water to be added to the system. If you are lucky, the union is placed so as to allow a pump to charge the system with air. Then, you are ready to mount a full scale union fixing project. but, it's kinda fun if you like that sorta thing!

Not a huge fan of dielectric unions...


  • Dave_61
    Dave_61 Member Posts: 271

    We have a dielectric union that has a slow leak. I know that many people on this board are not crazy about them. It was fine all winter but seems to drip now that the boiler only is running intermittently. I bought a high temp gasket (EDPM) and am hoping this will do the trick as it is close to the output of the boiler. However, I could not budge the union with 2 pipe wrenches. Are there any other tricks anyone has up their sleeves? I even put a length of pipe on one wrench to increase the torque, but no go. Thanks.
  • bob young
    bob young Member Posts: 2,177
    new york city smackdown method

    take two hammers .one to smack on the square wrench pads as hard as possible & one to hold on opposite side to absorb the blow. you will just about be able to turn by hand.
  • Mike C._4
    Mike C._4 Member Posts: 56

    Two hammers will work. I also use two hammers to tap opposite flats in the off direction at the same time (at an angle). Usually beats pipe wrenches for stuck unions.


  • Rich L.
    Rich L. Member Posts: 414
    Length of pipe

    Put your length of pipe on each wrench. Make em long enough and it'll break loose. Caution: If they're aluminum they may not be perfectly straight after you do this! Another caution: what ever trick you try, wear safety glasses while you're doing this. Anytime you start smacking fittings or anything else for that matter be sure and protect your eyes.

    Good Luck
  • Dan_53
    Dan_53 Member Posts: 20
    You guys are great....

    I stood a pipe wrench up under the fitting to wedge it tight and support it (fitting is about 1.5 feet off floor). Then I gave a few solid whacks with small sledge. Came right apart. Thanks again.
  • bob young
    bob young Member Posts: 2,177

    now that you took it apart, replace it with regular or flange union
  • Darrell_4
    Darrell_4 Member Posts: 77

    I usually just go out to the truck and get my hand DeWalt 18v Sawzall and cut the thing out prior to replacing it with a bronze union. Winds up being faster in the long run.
  • Dave_61
    Dave_61 Member Posts: 271
    Will the EDPM

    gasket also eventually leak? We have 4 or 5 unions in the system. The only one that leaks (knock on wood) is the one that is about a foot from the boiler output. Water temp gets to about 180 deg. The person at Watts Regulator said that EDPM gasket is made for steam/higher water temps and should solve problem. So far, no leak after replacement (again, knock on wood).
  • EricAune
    EricAune Member Posts: 432
    Right on

    What Darrell said is about right
    "If you don't like change, your going to like irrelevance even less"
  • what the die-electric unoins

    Doing on the heating system in first place? They are not needed and will leaks now matter what. Get rid of them all in same time. Less make up water when doing it so.
  • mtfallsmikey
    mtfallsmikey Member Posts: 765
    We had

    A local AHJ require them...for a brief period. You know the rest of the story....
This discussion has been closed.