Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Copper pipe connecting new radiator

We just had a new radiator installed in a bathroom we just built.  The plumber used 3/4" copper pipe to connect the radiator to the vertical supply line.  We have a 1 pipe system.  There is a water hammer when the system first heats up.  We had another plumber take a look at the system and he freaked us out about the copper, saying it would burst in 5 to 10 years. Should we make our contractor rip up the tile floor so we can have the pipe replaced with steel or iron?  Are we over-reacting?   Is it ok to leave the copper pipe, knowing we will always have a small water hammer?


  • strike while the pipe is still hot!

    get this installation right in the beginning, while the contractor is still around! in my experience, these situations only get worse as time goes on-not better. the problem with copper pipe in steam systems is the different expansion it has vs. iron pipe. the soldered seams may well twist apart, and leak at some unpredictable time in the future-usually friday night before christmas, with all your relations staying over! check the new installation for a few days before covering the new pipe up.

    while you are replacing this pipe, get the plumber to show you how to perform routine maintenance, such as checking the pigtail for occlusion, which could make the pressure too high, and the main vents for proper operation. putting a low-pressure gauge, and vaporstat on would be a plus as well.

    more maintenance items are discussed in "the lost art of steam heating" available at the shop button above, which demystifies these wonder heating systems.--nbc
  • Jamie Hall
    Jamie Hall Member Posts: 19,966
    That water hammer

    isn't because of the copper.  Although the copper shouldn't be there, for sure -- he should have used black iron, like a good boy.  First off, the copper is too small -- the feed to one pipe steam radiator should be 1", minimum, and it doesn't matter what metal it's made of.  Second, I'll bet he didn't put enough pitch on it, either.  Might have -- but I wouldn't be too optimistic.

    Normally I'd say not to worry about the copper.  It's not a good idea, but it's not the end of the world either, if it's properly installed.  However, in my humble opinion, this one may well give you trouble (as NBC says, at 11:00 PM, Christmas Eve, with a blizzard going), as I would regard the combination of water hammer and copper as just plain lethal to that poor piece of pipe.  I'd get it fixed, myself...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
This discussion has been closed.