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One pipe boiler system

The main run is 1.25 can I add 12ft of baseboard using 3/4 and how many feet can I go 


  • Ironman
    Ironman Member Posts: 7,385
    You question is somewhat vague. Are you saying that you have a Monoflo system with a 1.25” main? And are you asking if you can add 12’ of BB that’s teed off of that main or are you asking if you can run the 1.25” main directly through the BB? The answer to the latter would be no.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Lance
    Lance Member Posts: 272
    You may add whatever you want. The question remains will it do what you want?
    EBEBRATT-Ed Member Posts: 15,722
    12 feet of baseboard only needs about .7 gpm. You can use 1/2 Inch branches to the new baseboard. Space the tees 12" or more apart do not put them close together. Use a regular tee on the supply pipe and a Monoflo or venturi tee on the return. Don't forget to install an air vent.

    using 3.4" might steel some heat from another room.

    Pitch the branches from the main to the baseboard up slightly if possible.