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

Single Loop with Diverter Tees

drosnerdrosner Posts: 33Member
hi - i'm adding to an existing hot water heating zone with several new baseboards. I want to control each baseboard with a TRV. After much research I believe the best way is to create a single loop for the zone and then use diverter tees (monoflows) at the supply and return of each baseboard to connect to the main loop. That way I can shut down any of the individual baseboards without impacting the others. I've included a basic picture that also shows the baseboard lengths and required BTUs for each room.

Is this the right way to go for this? If so how do I determine if I need a diverter at both supply and return? Do i have to worry about the distance between the supply and return tees?


  • IronmanIronman Posts: 5,107Member
    Since I'm not aware of any TRVs that also have a bypass, I'd have to say no. You can't shut off flow in a Monoflo system... Unless you can find a TRV that has a bypass.
    Bob Boan

    You can choose to do what you want, but you cannot choose the consequences.
  • drosnerdrosner Posts: 33Member
    I was thinking the TRV connects right to the side of the baseboard and is fed by a section of pipe from the main loop. I would only be shutting off flow to a single radiator and never the main loop.

    Is that not correct?
  • IronmanIronman Posts: 5,107Member
    You can't shut off flow to the rad's in a monoflo system without adding too much head that will effect the flow in the main.

    I would recommend that you look at doing a homerun/ manifold system with a delta P ECM circulator if you want to use to TRVs.
    Bob Boan

    You can choose to do what you want, but you cannot choose the consequences.
  • EBEBRATT-EdEBEBRATT-Ed Posts: 5,914Member
    @Ironman is correct
  • newagedawnnewagedawn Posts: 549Member
    keep the tee's within 6 inches
    "The bitter taste of a poor install lasts far longer than the JOY of the lowest price"
  • HenryHenry Posts: 914Member
    You don't need two monoflow Ts if feeding from below. I have seen some installs of TRV on a monoflow system. It is not one of the best ideas.
  • cuttercutter Posts: 252Member
    Listen to Ironman, I don't know if he mentioned a 2 pipe direct return or a two pipe reverse return. Listen to the pros and do the job right. Just my two cent's
  • drosnerdrosner Posts: 33Member
    I've been doing some more research including this site and some are saying it's one way to do it but can go wrong if the trv and rad add too much resistance then you don't get flow and it appears like an air lock problem.

    A 2 pipe rerun might be cost prohibited and I'm now considering only adding trv to 2 of the long rads. On one of the dan H articles he suggests doing a 1/2" by pass to do what I'm attempting to do. Any thoughts on this approach?
  • unclejohnunclejohn Posts: 1,374Member
    You can run all that in 1/2' copper. And the 2, 3 and 4 footer in 3/8".
  • Paul48Paul48 Posts: 4,492Member

    You could use a 560 series zone valve. Just a thought....
Sign In or Register to comment.


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