Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.

If you've found help here, check back in to let us know how everything worked out.
It's a great way to thank those who helped you.
Need to contact us? Visit

Joining cast iron baseboard units side-by-side, not end-to-end

BoatsterBoatster Posts: 4Member

I want to join four cast iron Burnham BaseRay 2-foot units together in a floor joist bay to heat the room above. But I want to mount them standing side by side, not end to end the way they were designed.

My question is: How do I hook up the water supply/return pipes? I want to make sure the water flows properly and evenly to all four units. So, in the attached image (top view, looking down), do I use the 'snake' method in Drawing A or the 'manifold' method in Drawing B?

Also, am I correct that I'm installing supply pipes only on the bottom opening of each unit, with the top openings either capped off or for the air release valves?



  • IronmanIronman Posts: 5,013Member
    edited January 6
    Why would you wanna do this? Radiant pex and heat transfer plates would be less expensive and give more output.

    And no, neither drawing is correct. The top and bottom connections need to be joined on each section except the last where a vent is installed on the top.
    Bob Boan

    You can choose to do what you want, but you cannot choose the consequences.
  • NY_RobNY_Rob Posts: 1,369Member
    I think you're going to have airflow issues on any of the stacked radiators. Cool air is supposed to be drawn in from the bottom and hot air exits the top cutouts. In your configuration hot air (not cold) will be pulled in from the hot unit below it.
  • Jamie HallJamie Hall Posts: 10,407Member
    B is going to give you much better results -- much more even assuming that you build a similar manifold on both sides (sketch shows only one...). Try to keep the pipe lengths and the numbers and types the fittings as like as possible; that will help the evenness.

    And yes, the pipes go in the bottom openings. Use the top opening at one end of each uit for a bleeder or air release -- and do yourself a favour and pitch the units slightly up towards the end with the air release...

    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
  • BoatsterBoatster Posts: 4Member
    Thanks all. Very helpful. I should have made clear that I was not suggesting installing BaseRays underneath the wood floor itself. The recess is already cut out of the floor with a vintage steel grill covering it., and I have two BaseRays there now which have been operating fine but not generating enough heat for the room. They are linked using a manifold approach so I was really just confirming that same approach would work for four as well as two units.

    Appreciate everyone's help. This is a great forum!
  • EBEBRATT-EdEBEBRATT-Ed Posts: 5,734Member
    BaseRays set below the floor with a grill will not work very well unless the grill opening is very large, even then it may be problimatic

    BaseRay needs air flow from the bottom to the top like a chimney.

    You may not get enough heat installing them that way

    too small an opening will not allow cold return air to sink down into the opening. If cold air can't get down there heat will not come out
  • JohnNYJohnNY Posts: 2,249Member
    Shouldn't this be piped in a balanced reverse return configuration? First one supplied is last one returned to the boiler?
    For installations, troubleshooting, and private consulting services, find John "JohnNY" Cataneo here at :
    "72°F Mechanical, LLC"
    Or email John at [email protected]
    John is a professional Master Plumber, licensed by The Department of Buildings of The City of New York, and works extensively in NYC while consulting for clients in and out of state.
  • BoatsterBoatster Posts: 4Member
    EBEBRATT-Ed and others. I see what you mean about insufficient cold air supply. How about if I run something like a PVC pipe from the bottom of the joist bay box where the BaseRays sit straight out to just below the ceiling of nearest open room? If it's, say, 1.5" or 2" PVC would that pull enough colder air from the room through the joist bay and directly into the box?
  • IronmanIronman Posts: 5,013Member
    Probably not. You need as much free area for that as there is on the top opening.
    Bob Boan

    You can choose to do what you want, but you cannot choose the consequences.
  • EBEBRATT-EdEBEBRATT-Ed Posts: 5,734Member
    This is a guess. 1 1/2" wide opening x #of feet of baseboard might be enough opening.

    So the 4 2' sections you mention would be 4 x 2=8 x 12"=96" x 1 1/2"=144 square inches= a 12" x 12" opening
  • BoatsterBoatster Posts: 4Member
    edited January 8
    OK, got it. Thank you so much for all the help, people.
Sign In or Register to comment.


It looks like you're new here. If you want to get involved, click one of these buttons!