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Connection from imbedded Pex to CI radiator?

Bomack Member Posts: 2
Renovating my 2-story building. It was heated by a circulating hot water system with cast iron radiators. I may want to reuse some of the decent looking existing 1930’s CI radiators to heat the renovated cellar or perhaps use new cast iron baseboard. Rather than have piping coming down from ceiling I’d like to feed the six radiators individually via a manifold w pex S/R feeds embedded in the slab. Mod-con system design max temp 140 degree. Should I decide to use a floor-mounted radiator, the clearance from top of concrete to the connection could be minimal, less than a few inches. Can anyone recommend an assembly for such connections?


  • Zman
    Zman Member Posts: 7,572
    Using copper stub outs though the floor works pretty well http://www.supplyhouse.com/PEX-Crimp-Fittings-543000

    As long as you get the spacing correct, you field cut and sweat on a union when you trim it out. Generous pipe insulation will prevent contact with the concrete and give you a bit of wiggle room on the alignment.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • hot_rod
    hot_rod Member Posts: 22,245
    Make a template to hold the stubs plumb, and exactly where you need them.

    A 2X4 with 1-3/8" holes allows you to drive in the plastic insulator bushings to hold tight to the tube. 1/2" wall insulation around the stub in the slab, and a standard chrome or plastic escution will cover the foam.

    Or dig the foam out and grout the stubs in once the radiator is in place, to bug proof it.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Bomack
    Bomack Member Posts: 2
    Been away, thanks to both for replying.