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Grundfos circulator

slick
slick Member Posts: 3
in THE MAIN WALL
I just picked up a new grundfos circulator,it's a three speed with a check valve in it.this is my first time replacing one in my broiler and need some advice.i have flow control valves on all my zones,do I have to remove the check valve in this circulator before I install it.thanks Chris

Comments

  • slick
    slick Member Posts: 3
    I'm guessing I don't need it,I'm a rookie at this boiler stuff.i would like an expert to jump in,before I start tearing stuff apart.
  • hot_rod
    hot_rod Member Posts: 22,787
    If the flow control valves are working you could remove the check. It doesn't present much pressure drop if you leave it in.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • icesailor
    icesailor Member Posts: 7,265
    hot rod said:

    If the flow control valves are working you could remove the check. It doesn't present much pressure drop if you leave it in.

    That's true (maybe) but if both checks are working, they can set up positive and negative zone between each other.

    Also, according to the performance curves published by Taco for (say) oo7 circulators, there is a significant decrease in performance with IFC's in place because their small size causes unwanted restriction.

  • hot_rod
    hot_rod Member Posts: 22,787
    He mentioned Grundfos, here is the curves with and without the supplied check. Very little difference in output, doubtful it would be noticed.


    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • slick
    slick Member Posts: 3
    I guess the numbers don't lie,but looking at that check valve,you would think the flow would be restricted more then that.im taking it out,and thanks for the reply I feel better now.
  • icesailor
    icesailor Member Posts: 7,265
    edited March 2015
    I was only going by Taco's published performance curves.

    A Taco 007 without IFC's:

    http://www.taco-hvac.com/uploads/FileLibrary/curves003-008.pdf

    With IFC's: 17.5 GPM@8.75" of head.

    Without IFC's, 23.5 GPM @ 9.75+' of head.

    I'll take the flow & head over the restriction. Might make cavitation and put air in the system.

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