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Squeaky Grundfos

Post in 'The Boiler Room - Wood Boilers and Furnaces' started by Nofossil, Feb 13, 2013.

  1. Nofossil

    Nofossil Moderator Emeritus

    Joined:
    Oct 4, 2007
    Messages:
    3,415
    Loc:
    Addison County, Vermont
    I recently installed a new Grundfos 15-58 FC that had been sitting on a shelf in my basement for a few years. Worked fine for a week or so, but now it squeaks (or maybe 'whistles' is a better word).

    It doesn't do it all the time, and it seems to be more likely at lower speeds. It's gradually getting louder.

    Is there any likely solution besides replacing it?

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  2. Clarkbug

    Clarkbug Minister of Fire

    Joined:
    Dec 20, 2010
    Messages:
    1,013
    Loc:
    Upstate NY
    Are the Grundfos pumps like the Taco ones in that they have a replaceable cartridge? Maybe thats the cheaper solution?
  3. Mushroom Man

    Mushroom Man Member

    Joined:
    Sep 6, 2008
    Messages:
    183
    Loc:
    Eastern Ontario
    I have 8 Grundfos 15-58 pumps in my system. They have been in operation 4 years now. One of them, out of the box squeeked initially. I took the cover off by removing 4 screws and found a break in the rubber gasket (o-ring) that seals that cover. I repeat that was right out of the box. I replaced that gasket and have had no further issues. None of the other pumps have given any hint of problem although I have expected issues since one pump is on the open side of my unpressurized storage tank.
  4. Nofossil

    Nofossil Moderator Emeritus

    Joined:
    Oct 4, 2007
    Messages:
    3,415
    Loc:
    Addison County, Vermont
    I'll try a cartridge swap and check the gasket at the same time. Of course, I might end up with two squeakers :-(
  5. TCaldwell

    TCaldwell Minister of Fire

    Joined:
    Oct 26, 2007
    Messages:
    532
    Loc:
    860-868-9014 h 203 948 0864 c nw corner ct.
    I have 6 of these in service, this squeaking has started with me on low speed with 3 of them at different times. Usally the circulator will stop working within a week or so of the squeak start. if i remove the cartridge it is somewhat bound,usally blowing compressed air through the center of the impeller and flushing with clean water and rotating the impeller by hand forward and backward will help to loosen it up. good luck
  6. Duetech

    Duetech Minister of Fire

    Joined:
    Sep 15, 2008
    Messages:
    1,436
    Loc:
    S/W MI
    I have a 15-58fc that did that shortly, within a minute or less, after installation. Bumping it up to max speed stopped it but going to lowest speed made it start again. I thought maybe it was air and ran the unit at high speed for several minutes after the noise stopped (it howled and purred sporadically several times to the point I though I had just toasted another pump). I am at "middle" speed now and have no noticeable noise and the house is warm. Not that it made a difference the squeal occurred during a low system temp via a system protection tempering valve. By the time the pump had run at high speed for several minutes the water was hot enough to activate the valve. So possibly the hotter water was able to induce a better purge once the valve activated???!!??
  7. Bob Rohr

    Bob Rohr Minister of Fire

    Joined:
    Jan 9, 2008
    Messages:
    764
    Loc:
    SW Missouri
    What pressure are you running on the system? The like to have some positive pressure, they are not well suited for open systems. Is it mounted with the shaft horizontal? Fluid quality? The system fluid needs to travel through the shaft to lubricate the bearing in the cartridge.

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