Previously, I’ve talked about a few ways to quiet a noisy sump pump. One of the most common noises is a gurgling sound that happens just as the sump pump shuts off. It’s a somewhat common sound, but also one that can drive you up the wall if total silence is your goal.
Gurgling noises are often the result of water flowing back down the discharge pipe after the pump cycles. At the same time, air rushes back up the discharge pipe, leading to a siphoning effect that causes gurgling noises after the pump stops running.
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How to Stop Sump Pump Gurgling Noise
This guide gives you detailed information on how to diagnose and fix your sump pump’s gurgling issues. These tips are easy enough for casual DIYers to tackle.
1. Replace the Check Valve
Most sump pumps employ a flapper-style check valve near the discharge pipe that allows water to flow in one direction as the sump pump runs. In the case of a gurgling sump pump, however, the flap may not be strong enough to close quickly or it might not close properly, allowing air and water to slip by. What you get is several seconds of gurgling water at the valve.
Replace your old flapper-style check valve with a spring-loaded check valve. The latter’s spring-loaded action is much stronger than the traditional flapper. Not only does it close smoothly as the pump comes to a stop, but it also stays closed to prevent water from traveling back down the discharge pipe. The Campbell Check Valve is an excellent choice.
- BRADY
- Package Length: 10.8"
- Package width: 13.79"
2. Adjust the Pump Switch Height
Sump pumps should stop running before the basin runs dry. Otherwise, the pump ends up sucking air along with what little water remains, leading to slurping and gurgling sounds.
Adjust the pump switch height so that the sump pump stops short of running dry. Check the pump switch mechanism and make sure its movement isn’t impeded by rust or corrosion.
3. Add a Weep Hole
Sump pumps can become “air locked” as air flows back into the pump chamber. Air locks can block the sump pump from pushing water through the pump and the discharge line. The end result is a dry pump motor that could potentially overheat and burn out.
The solution involves drilling a weep hole to help purge trapped air from the pump. Use a power drill to bore a 3/16-inch hole between the discharge pipe and check valve. Make sure the hole is drilled at a 45-degree downward angle below the water line. If your sump pump already has a weep hole, make sure it’s not clogged with debris.
Related: Top Quiet Sump Pumps for Your Basement
4. Clear Any Debris in the Discharge Pipe
Any restriction in the flow of water through the discharge pipe can cause it to travel back down the pipe and check valve. Over time, however, debris or gunk can build up inside the pipe. This can slow down or even stop water flow within the pipe.
Disconnect the discharge pipe from the rest of the sump pump and clean out the pipe thoroughly with a plumber’s snake or a metal hanger wire. Use a high-pressure hose to flush out any remaining debris inside the pipe.
5. Add a Fitted Basin Cover
You can minimize gurgling noises significantly, but you may not be able to get rid of them entirely. An open sump pump basin can amplify minor gurgling noises, allowing them to echo throughout your home.
Adding an insulated and fitted basin cover may take care of the problem. The added insulation helps dampen the noise while reducing vibration. While new sump pump kits often come with their own insulated covers, you can make one on your own with thick foam insulation or MLV sheets.
Did you Add a Backup Pump?
Sometimes everything works just fine…right up to the moment you decide to modify your existing sump pump setup. Adding a backup pump can throw things out-of-whack in unusual ways, including a newly discovered gurgling noise from the main pump.
In one example I’ve personally encountered, water continued to flow out of the discharge line after the main pump turned off, creating a vacuum. A weak check valve allowed air to be pulled into the discharge line. The gurgling stops as soon as the line is empty or the vacuum breaks.
Double-check your backup pump installation and make sure the install directions were followed to the letter. Consider installing a vacuum breaker, otherwise known as an air admittance valve, someplace after the main and backup pumps.
Conclusion
Just because your sump pump likes to gurgle doesn’t mean you have to live with the noise. The simple tips above offer plenty of workable options for eliminating gurgling sounds, thus bringing a welcome measure of peace and quiet back to your home.
*Last updated 2025-03-15 at 16:54 / Product Links & Images from Amazon Product Advertising API
