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pump speed

Kal Row
Kal Row Member Posts: 1,520
Rule: a spring check needs 11 diameters of straight pipe behind it to smooth out the water flow or it will rattle, this is why taco puts them in the eye, if you have FC pumps with them in the pump’s discharge, open it up an check it for dirt – cause even a little will make it chatter like hell


  • Timco
    Timco Member Posts: 3,040
    pump speed


    Here I am...a happy HO. Pumping away (from the point of no pressure change) and now the swing-check valves were rattling through the system, but all else is perfect. I have 3 zones with grundfos ups 15-42-f pumps, set to speed 3. When put on speed 2, rattling lessened. On speed one, no rattle, and no boiler crackel or anything of the sort. Is setting 1 too low? Each zone aprox 70', 2 zones 11/2" and one 1". All reduce to 3/4 at the pumps and at the return swingchecks, with 1" manifolds. Any reason to have them up on 2 or 3 when seems to be fine on 1?

    Thanks yet again, if this were a major problem, I would find a pro (allthough there is not one listed for the Salt Lake City area). I appreciate the help on these little annoyances.

    Tim White
    Just a guy running some pipes.
  • .
    . Member Posts: 80

    If you are getting enough heat, even to the furthest radiator, the that pump speed should be fine. Generally, just like boilers, pumps are way oversized. There is no advantage to having a higher flow rate than necessary, and noise and electric power consumption are disadvantages.
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