Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Installing check valves in a two zone system.

JackW Member Posts: 218
I am redoing my radiant heating system in my Morton building, all piping is 3/4". It is a two zone system, each zone is controlled by a pump. In the old setup I kept the temperature in zone 2 higher and never had to set the thermostat in zone 1 because the zone 2 pump would pull water past the zone 1 pump heating zone 1, not as warm as zone 2 but ok. I want to put check valves ahead of the pumps to prevent this parasitic draw but I'm afraid the 3/4" check valves will restrict the flow. When in the open position the stopper hangs partially down which I would think would restrict the water flow. Is this a concern or not? Any thoughts on this will be greatly appreciated.



  • Zman
    Zman Member Posts: 7,446
    Unless your pump sizing is marginal, the addition of the check should not be an issue.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • JackW
    JackW Member Posts: 218
    Good to know, thank you for your response.
  • Simply Rad
    Simply Rad Member Posts: 172
    Grundfos 3 speed pumps come with integral check valves
    Jeffrey Campbell
  • JackW
    JackW Member Posts: 218
    Thanks Simply Rad I'll look into that.