I have a new condition with my sump pump. It runs for a few minutes (like normal) and then it stops for a few seconds and runs for a few seconds over and over (maybe 10 times). This happens every time the sump pump runs. It has been doing this for the last couple months and I'm concerned that this is causing additional wear on the pump. I installed a battery backup pump on the same outbound pipe last fall, but it has been running fine with that install for many months.

Any ideas on the cause or how to narrow down the cause?

1 Answer 1


I'm not a sump pump expert, but it sounds like perhaps your check valve isn't working properly. If it isn't closing fully then water in the pipe can drain back down into the sump when the pump stops. If enough water is able to drain back down then it would cause the pump to start again.

Assuming you actually have a check valve, it probably looks something like this:

enter image description here

The lower the check valve is installed, the less water will be able to drain back down.

  • Ahhh, that sounds likely. I will check this out. Thanks! Commented Oct 24, 2012 at 16:53
  • 2
    Good thought. Typically the "on" and "off" levels are far apart, and some pumps have a way to adjust this (a dial, or a couple stoppers on the rod the float is suspended from). Even if water is draining back in, the "on" level should be higher enough than the "off" so that this doesn't happen. You can check the distance manually by lifting and lowering the float. If this is the problem, you'll also hear/see the float clicking on and off.
    – gregmac
    Commented Oct 24, 2012 at 17:38

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