(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 5 of 5

Thread: Two recirculating lines and one pump?

  1. #1

    Question Two recirculating lines and one pump?

    Is it possible to have two recirculating hot water lines connected to one recirculating pump?

    I'm currently putting in my copper pipes (new construction) and was going to install two return lines to go back to the water heater. One loop will go to the master bath and be ~110' total length (3/4" supply & 1/2" return together). The other loop will go upstairs and be ~95' total length (3/4" supply & 1/2" return) with a 10' rise from the basement to the second floor. About 10' of the supply will be shared between the two supply lines (1" line until the master bath branches off).

    I'd like to be able to connect the two return lines together before the pump and use one pump. I was looking at the Laing SMT-303 pump which is able to handle up to a 250' total supply & return length. Adding both of my lines together I'm at 205'. Should this work?

  2. #2
    Plumber jimbo's Avatar
    Join Date
    Aug 2004
    San Diego


    In theory this would work, but you will have to design components into the system to balance the flow in the two loops( check valves, flow regulators, etc.)

  3. #3
    Plumbing Designer FloridaOrange's Avatar
    Join Date
    Dec 2005
    SW Florida


    Yes you can do what you want. You will need some sort of balancing valve to tweak the return flow from the two systems.
    Semi-professional plumbing designer
    Enjoying life in SW Florida

  4. #4


    Is there another "preferred way" to handle a situation like this? Is a two pump setup something I should be considering? I'd like to have something cost effective.

  5. #5
    Moderator & Master Plumber hj's Avatar
    Join Date
    Aug 2004
    Cave Creek, Arizona

    Default pump

    You do not add the two systems together to get the pump size. You go by the largest/longest one. One pump with modulating valves on the two lines at the point where they merge together will work just fine.


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts