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B&G 100 Pump chatter noise

JohnKJohnK Member Posts: 7
edited January 15 in THE MAIN WALL
I’m hearing a chattering noise at startup which eventually goes away after a few seconds.

First I oiled it to see if it helped (added too much as it leaked)

I replaced the coupler and motor mounts but still hear the same noise. The old motor mounts didn’t appear to be sagging at all.

Please watch this video to hear the noise!


  • STEVEusaPASTEVEusaPA Member Posts: 4,205
    Are you sure the coupling was installed correctly? Which one did you use? Sounds like the one that makes an 'X' instead of the one that looks like 2 wheels.
  • EBEBRATT-EdEBEBRATT-Ed Member Posts: 7,091
    Take the motor off and run it by itself see what that sounds like.

    The coupling has to pull the springs, not push them there are a couple of different couplings.......make sure you have the right one. Turn the bearing assembly and see what that feels like. Make sure the coupling set screw in in the recess in the shaft
  • JohnKJohnK Member Posts: 7
    edited January 16
    The new coupler looks like the old one. Both the new and old were making the same chattering noise...well, the old one only recently started making noise. It was the original coupler because it had red spray paint..

    I will try running it with the coupler and motor taken off..
  • GordyGordy Member Posts: 9,523
    Were the motor mounts replaced? Usually worn mounts create a misalignment of the shaft to the coupler causing it to fail.
  • STEVEusaPASTEVEusaPA Member Posts: 4,205
    edited January 16
    I usually use one that looks something like this:

  • JohnKJohnK Member Posts: 7

    When I turn the motor shaft with my hand, I do seem to hear one click per turn.

    I haven’t tried turning the bearing assembly shaft...

    @Gordy yes I replaced the motor mounts (but the old ones seemed pretty good shape)
  • retiredguyretiredguy Member Posts: 227
    edited January 17
    Sounds like a problem with the spring coupler or a loose or bad impeller, or watch the coupler closely when the motor starts up. , Does the coupler turn smoothly or does it jerk slightly or shake when making that noise. The problem could be a bad or worn start switch in the motor or that the motor needs replaced.
  • B_SloaneB_Sloane Member Posts: 54
    Starting Switch
  • JohnKJohnK Member Posts: 7
    i switched from a 100 to a nrf-33. Quiet
  • HVACNUTHVACNUT Member Posts: 3,412
    Smart move switching to a wet rotor pump.
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