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Panel Radiator Stub-outs: Copper or PEX?

ewang Member Posts: 77
I'm at the point where I am going to be stubbing out the connections for my panel radiators in the basement and I'm trying to decide what stub-outs to use for the angled valves that attach to the panel radiators. I'm using 1/2" HePex for all of my runs back to the manifold.

The pex option is just adding an EP elbow that is unsecured in the wall and adding a 8" stubout for rough-in, which would be trimmed to fit once I get to installation. I have concerns about UV degrading HePex and the unfinished look of pex. I know I can add some chrome covers to glam it up and I feel pretty comfortable with the pex compression fitting to the valve.

The other option is to purchase a pex to copper elbow stubout such as the item below. This would make rough in location critical, because once fixed in position, there will be no horizonal or vertical movement possible. But this would also help hold the panel radiator in place. Aside from bathroom style compression fittings, I have no experience in their reliability.

Any words of advice or stories of good/bad with either case?



  • nosirra1Arrison
    nosirra1Arrison Member Posts: 53
    You will need to secure the pex within the wall or it will expand as it warms and will “knock” inside the wall.

  • psb75
    psb75 Member Posts: 730
    Those pex pipes will hardly be visible. below the rad, coming out of the wall. You also have the option of covering them with white pvc sleeves--same color as baseboard and radiator. Boom done!
  • ewang
    ewang Member Posts: 77
    @nosirra1Arrison Those pictures sure help put it into perspective. Thank you
  • Zman
    Zman Member Posts: 7,467
    I think either copper or PEX with covers will work nicely. It really is a personal preference.
    The one nice thing about those radiators is that they rough in nicer than the thinner models like Runtal. You can install and pressure test the valves at rough in then simply connect the unions.

    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • ewang
    ewang Member Posts: 77
    @Zman For sure, that's what attracted me to the panel radiators over the Runtal offering. I think I'll go with Pex since I'll have all of the components already - just need to come up with a good looking cover.
  • TAG
    TAG Member Posts: 751
    I used the clip on metal things that make a 90 turn out of the Pex. Can't remember what they are called -- makes for no joints in the wall. Ran the Pex in insulation with just enough hangers to keep it safe. It's just floating at the 90's Never hear anything . The thicker radiators hold the valve further from the finished wall .... with the thinner ones I actually used a strip of pine behind the wall mount to bring them out a bit and make the valve proud of the finished wall. They also seem to work better that way

    The Runtals do require a bit more thought -- not much space,

    On a few occasions where there was not enough space to make the 90's work -- like in a basement with thin studs against the foundation. Hard piping copper to a nearby connection point was the only solution. I guess today with all the Pex connectors -- that would not be required.