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can hot water radiator supply lines be dropped 6" for ~5 feet?

RunnerSt Member Posts: 1
I am moving a radiator in a hot water system about 10 feet. The bathroom's floor joists are 2X6s @16" where the radiator is now and about halfway to where I want to end up they become 2X12s @24". The ceiling below this room is dropped about a foot, so the easiest approach is to run the existing supply and return lines to the 2x12's, drop them 6" and come up in the new location. Alternatively, I could drill through the 2x12's to maintain the height of the lines. If I go the easy route, I cannot really drain the system completely and I could trap air, but since the system is being pumped, does it matter which I do? Thanks


  • JohnNY
    JohnNY Member Posts: 2,718
    Doesn't matter. Just do it.

    Some will argue you'll be creating an air trap, which you could solve easily by using tees and air vents at the downstream high point of your offset behind an access panel but I'll bet you'll have no problem doing what you describe.
    Contact John "JohnNY" Cataneo, Master Plumber
    in New York
    in New Jersey
    for Consulting Work
    or take his class.
  • M Lane
    M Lane Member Posts: 123
    edited February 2014

    We do them all the time. I'm against remote air vents though, as I've seen plenty actually allow air in to the system. Just do a thorough job of purging and make sure you have an effective air eliminator at the boiler.