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How to loop 2 cast iron rads

jonny88 Member Posts: 1,139
HI all.Customer lives in an old georgian house .House is 3 stories and is on one zone,a large gravity system.On the top floor there is a bathroom with a cast iron rad.In the bedroom 6 ft away is another cast iron rad.The bedroom radiator has a seperate feed and return coming from basement.At some stage the riser to this rad was disconnected.The bathroom rad works fine.Im assuming there was a leak or some issue with the bedroom rad.Heres my ?.Can i make a loop with the bathroom rad and bedroom rad.I was looking at systems etc on the site and can't find a drawing that shows the correct way as I am figuring air will be a problem.Thanks in advance for any input.


  • icesailor
    icesailor Member Posts: 7,265
    Loopy rads:

    If you "Series Loop" two radiators together, the first radiator has to fill with hot water before the second radiator fills. Experience shows that the second radiator never works properly.
  • Ironman
    Ironman Member Posts: 6,555
    Still Gravity?

    I agree with Ice that it probably won't work well, particularly if it's still gravity. If it's been converted to forced flow, you make it workable by adding a small circ on that riser, but the first rad will still heat up first.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • jonny88
    jonny88 Member Posts: 1,139
    thanks guys for your info

    i am actually going to install a manifold and run a homerun to each rad. Thanks for the advice.