I had a sump pump installed. Approximately a year later, after the pump runs, there is a loud gurgling noise accompanied by vibration from the pipes. During high water seasons, this leads to a constant and annoying gurgling sound.

The sump pump line goes (relatively) straight up ~8'. The check valve is located ~4' above the pump. Once the line hits the ceiling it runs horizontally ~15' then turns right 90 degrees, drops 6" to get under the beams, runs horizontally another 6' and then descends at ~45 degrees another 2' to where it turns left and exits through the foundation.

The gurgling seems to occur in the descent to the exit point through the foundation (based on sound and feeling the gurgles in the pipe). It doesn't seem that this would be due to a failing check valve because of it's young age and that the noise doesn't seem to originate near the valve (unless it's losing a necessary vacuum).

How can I reduce this noise?

  • 2
    That's a long discharge! You have a 25' drain line with no vent, I'm surprised you didn't have problems all along.
    – Tester101
    Feb 25 '13 at 14:11
  • Check the manufacturers documentation, it may have a limit on how long the discharge line can be. There also may be code limitation, but I'm not familiar with plumbing codes.
    – Tester101
    Feb 25 '13 at 14:33

If you have the clearance, you could put an air admittance valve at the high point of the drain. I'm not sure of the code on that, but since this isn't for a drain into the waste stack, it might be permitted. I would be reluctant to put it in a blind location though.

  • Would the fact that the sump is pumping the water out cause an issue with the AAV? Whats to stop the water from being pumped up against the AAV? (Water should not come out, but it would also prevent air coming in)
    – Steven
    Feb 25 '13 at 14:19
  • Yes, those concerns are the reason they are only sometimes permitted. In theory, they only open when the pressure outside the valve is higher than inside the pipe, at which point they allow air in. For a sump drain, especially if the basement is unfinished, I would have little concern with installing one. But I would be sure to install it where I'd see water on the floor if it failed. Here is a link that describes them, and answers some questions: plumbingsupply.com/autovent.html
    – Tim B
    Feb 25 '13 at 14:24
  • 3
    The key point is what Tester101 raises. The gurgling is water rushing down while air rushes back up the other way. That probably starts where the drain line starts to slope down, so I'd try installing the AAV there.
    – Tim B
    Feb 25 '13 at 14:26
  • Thanks for the advice. I purchased an AAV and will let you know how it goes.
    – Stephen
    Mar 5 '13 at 2:01

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