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Daisy chaining two radiators??

Hello -

We have a one pipe system that includes a radiator in the attic. The house is about 80 years old and the riser to the attic was placed on an inside wall. We are remodeling the attic and want to relocate the attic to an outside wall - which should be fairly do-able. The question we have is that we have an 'extra' radiator and wonder if it's possible to connect two of them together. (Our boiler has just enough EDR to handle the extra load). Can these two be daisy chained together or would we have to split them off at the riser? OR- is this just a non-feasible idea?

Thanks, Jeff

Comments

  • Jamie HallJamie Hall Posts: 10,401Member
    Steam radiators cannot be daisy chained -- you will have to create two separate runouts, one for each radiator.

    Check and make sure that the riser can handle the total EDR of the two radiators...
    Jamie



    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.



    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • ethicalpaulethicalpaul Posts: 694Member
    They can’t be split at the riser, Jamie?

    Although I would ask first what’s the vent situation up there. If it’s currently slow to heat maybe the existing radiator could do better with a change to the venting
    1 pipe Utica 112 in Cedar Grove, NJ, 1913 coal > oil > NG
  • Jamie HallJamie Hall Posts: 10,401Member

    They can’t be split at the riser, Jamie?



    Although I would ask first what’s the vent situation up there. If it’s currently slow to heat maybe the existing radiator could do better with a change to the venting

    Actually, I would split them at the riser -- didn't mean to imply otherwise. Any arrangement which will give a nice free drainage path for condensate should work.

    And surely whatever -- the venting should be adjusted as needed to have all the radiation in the place heat more or less together.
    Jamie



    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.



    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • jumperjumper Posts: 1,313Member
    Don't like long runouts. Call them branches.
  • CambelloCambello Posts: 7Member
    edited January 10
    Thank you the helpful comments. I didn't think they could be daisy chained but wanted to confer with the experts here just in case I was missing something. So - if I split them at the riser - would I have to make a " T " as in my little homemade diagram below?

    |_______ to rad 1
    | _______ to rad 2

    At this point, I'm just trying to explore all the options. We will never use this room full-time in the winter. Just as a guest room for a few days here and there.

    When we do use the single radiator that is currently in use, it heats up correctly and the venting works well. I am concerned that if I add a second radiator and split it off the riser, the two rads will fight for the steam.

    We live in Rochester, NY so it can get cold here.

    Thanks Again, Jeff
  • Jamie HallJamie Hall Posts: 10,401Member
    Indeed. Rochester can get a bit chilly.

    They won't fight. The only possibility of a problem is if the riser is too small to handle them. Unlikely, but it has happened.

    And any arrangement of fittings which will work. The objective is very simple -- come off the riser with the pipes to the radiator in such a way that you have adequate slope (1 inch in 10 feet) back to the riser from each radiator, with no pockets or dips where water can collect (and bang). Beyond that --whatever works.
    Jamie



    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.



    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • EBEBRATT-EdEBEBRATT-Ed Posts: 5,727Member
    If the riser is the correct size for 2 radiators (doubtful, nobody runs larger pipe than they need to) then the riser can be split but you would have to pull up a portion of the attic floor and with the existing riser across the room (depending on the distance) you may not be able to get enough pitch.

    Just a guess but a separate riser would most likely be a better option IMHO
  • CambelloCambello Posts: 7Member
    edited January 10
    Good points - the way things are situated, I can run the new piping above the floor (behind the new wall I’m building). The run is about 15 feet so I plan to set the radiator feet on bricks for the correct pitch. Given what I’ve learned here, I think I’ll just with a single radiator.

    I’ll make sure to insulate the new piping. I’m just not looking forward to skimming the boiler after adding the new piping.
  • ethicalpaulethicalpaul Posts: 694Member
    Wash it out real good with tsp or something that replaces it before your work and you may not have to!
    1 pipe Utica 112 in Cedar Grove, NJ, 1913 coal > oil > NG
  • CambelloCambello Posts: 7Member
    How do clean out 10’ section of pipe?
  • FredFred Posts: 7,849Member
    edited January 11
    If the riser is large enough to provide steam to two radiators, and you need more heat in that space, why not just replace it with a single radiator twice the size? I know you already have a spare radiator but they can be found very inexpensively, some even give them away to get rid of them.
  • ethicalpaulethicalpaul Posts: 694Member
    edited January 11
    Cambello said:

    How do clean out 10’ section of pipe?

    Put a cap on one end, fill it 1/3 full of water and detergent, put a cap on the other end, and slosh it back and forth repeatedly?

    I'm going to run a riser inside my living space from the basement to the 2nd floor, abandoning the old pipe in the wall, and I may try this myself.
    1 pipe Utica 112 in Cedar Grove, NJ, 1913 coal > oil > NG
  • CambelloCambello Posts: 7Member
    Thanks per the tip on cleaning the pipe - very easy and logical solution. Also, I like the idea of just replacing the radiator. I'm sure I can find one here in town. I think Dan's "Lost Art" book has some EDR charts so I can size the radiator properly. I'll check there and see what I find.

    Thanks -
  • Gary SmithGary Smith Posts: 271Member
    Don't forget to check the radiator feed pipe size against the EDR of the radiator you get. You want the pipe to be able to supply the heat capacity of the radiator.
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