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Close up of Basement Sump Pump System

How to Quiet a Noisy Sump Pump (10 Fixes)

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Sump pumps play a key role in keeping basements and crawl spaces dry. However, a noisy sump pump can take away the peace and quiet you expect in your home.

Sump pump noises can be disruptive and get in the way of many home activities, like watching movies or getting a good night’s rest. Loud sump pumps can also be a prelude to an eventual breakdown.

Fortunately, this guide teaches you how to quiet a sump pump, but how one becomes noisy in the first place. These actionable tips will help bring some peace back into your home.

Why Is My Sump Pump So Loud?

The sounds a sump pump makes can give clues to any number of underlying issues. Let’s take a look at some common noises and the issues that could potentially cause them:

  1. Excessive Vibration – Excessive sump pump vibration could result due to an improperly mounted pump. Poorly placed pipes as well as excessive angles and joints in the drainage pipe can also cause vibrations.
  2. Excessive Motor Noise – Sump pump motors tend to get noisier as they age and experience increased wear and tear. An improperly installed unit can also be noisier than expected. A large accumulation of rust or corrosion can also lead to increased noise.
  3. Clanging Check Valves – A slight metallic clang on startup is normal for most sump pumps, but constant clanging could be the result of a failing check valve. Older valve designs are also more prone to clanging than modern valves.
  4. Rattling and Banging – A poorly designed sump pit, with bad pump placement, as well as uninsulated pipes and lids, can also lead to excessive sump pump noises.
  5. Humming Like a Washing Machine – A soft, low humming is actually normal for sump pumps. It’s when that humming becomes louder than usual that you should start worrying, especially if it does not pump water.
  6. Slurping and Gurgling Sounds – You’ll hear these sounds as water flows back down the discharge pipe after the pump cycles. An improperly set float can cause the pump to run even when the pit is empty, leading to slurping noises.
  7. Non-Stop Running – A malfunctioning float pump switch, faulty check valve, or a clog in the discharge pipe can cause a sump pump to run endlessly.

What Should a Sump Pump Sound Like?

Before we get into what sump pumps should sound like, it’s important to know how they function. Sump pumps work by collecting excess groundwater before it has a chance to flood your basement or crawl space, especially after storms and heavy rainfall.

Sump pumps are usually installed in a gravel-lined sump basin located at the lowest point of the basement or crawl space. Water drains into the pit through the soil or multiple drains. Before the water rises out of the pit, however, a float arm or sensor trips the sump pump into action.

The pump uses a motor with a built-in impeller to pump water out of the pit through a discharge pipe. A check valve forces the water one way, preventing it from rushing back into the pit. The discharge pipe also channels the excess water out of the home and away from the foundation.

Sump pumps come in submersible and pedestal forms. True to their description, submersible sump pumps rest inside the water with the motor and other critical components shrouded in a waterproof housing.

With a pedestal pump, an inlet pipe extends into the pit to draw out water while the rest of the pump remains out of the water.

A well-designed sump pump should run with no more than a faint humming sound, akin to the background noise of a refrigerator or HVAC system. While hearing the pump operate in the background can be reassuring, any excessive noises should be checked out as soon as possible.

10 Tips to Fix a Loud Sump Pump

Quieting a loud sump pump can seem like a challenge, but there’s plenty you can do to minimize excessive noise.

1. Enclose Pump Inside the Pit

We mentioned submersible and pedestal sump pumps a while back. The latter tend to be much noisier than the former, especially since the pump itself sticks right out of the sump pit. As a result, there’s nothing preventing the noise from echoing throughout your basement/crawl space and the rest of your home.

If you have a pedestal sump pump, consider replacing it with a submersible type. Submersible sump pumps are completely enclosed within the pump basin, below floor level, keeping the noise underground. These attributes make submersible sump pumps the quietest type on the market.

2. Add a Cover to the Pit

An uncovered sump pit is yet another common source of noise complaints. It’s not unusual to see sump pits that are left completely open to the basement or crawl space. Some homeowners aren’t bothered by this, but the gurgling and humming noises during normal sump pump operation can reverberate throughout your home as a result.

Adding a cover to your sump pit can drastically reduce sump pump noise. Most new sump pumps feature a plastic cover that provides an air-tight seal for maximum noise reduction. You can emulate this for older sump pumps by making your own lid from a piece of plywood. Adding a rubber gasket to your plywood lid helps reduce vibrations while creating a better seal.

A sump pump cover also keeps objects from falling into the pit. This can be helpful if you have small children and/or pets and don’t want them to play around with the sump pump.

3. Insulate the Cover

Insulation can do wonders for muting sump pump noises. Modern sump pumps come with sound-deadening sump pump covers for this very reason. If you’re making a plywood cover for an older sump pump, you can line the underside with foam insulation, or thick MLV sheets to keep noise levels low.

Don’t forget about the rubber gasket mentioned earlier, as this also helps reduce unwanted vibrations.

4. Add a Grommet to Discharge Pipe

The flow of water through your sump pump’s discharge pipe can cause it to rattle against the sump pump lid, resulting in excessive vibrations and noise. Unsurprisingly, sump discharge pipe vibrations are another common source of sump pump noise complaints.

Fortunately, you can nip these vibrations in the bud by placing a rubber grommet between the discharge pipe and the sump pump lid. The grommet helps isolate the discharge pipe from the lid, absorbing vibrations from water flow while holding the discharge pipe still.

Adding a grommet also seals gaps in the sump pump cover where the discharge pipe normally passes through. You can do this for other pipes and lines that pass through the cover.

5. Insulate the Discharge Pipe

As water flows through the pipe, the resulting vibrations can cause the pipe to bang against the floor, the basin, or nearby walls. Wrapping sound-absorbing insulation around the discharge pipe not only mutes the sound of water sloshing through the pipes but also dampens contact between the pipe and nearby structures.

6. Reroute the Discharge Line

Your sump pump’s discharge line should have as few bends as possible. Too many bends in the line not only decreases water flow while increasing noise but also makes the sump pump work harder to push water through. If left alone, a poorly routed discharge pipe will condemn your sump pump to an early demise.

Consider rerouting your pipes to remove multiple, sharp bends. Instead of 90-degree angles, use no more than two 45-degree turns to reduce noise and maintain good water flow. These improvements will also keep your sump pump motor from overworking.

7. Adjust the Float Height

It may come as a surprise, but you don’t want the sump pit to run completely dry. Doing so causes the pump to suck in air as well as the small amount of water left in the basin. The end result is a series of gurgling or slurping noises. If you’ve ever tried to suck up the last bit of drink from a straw, then you’ll recognize that annoying sound.

Fortunately, you can avoid that problem by making sure the float height is adjusted properly. Adjust it so that the sump pump stops running just before the basin is completely dry. You’ll want at least a couple of inches of water in the basin to prevent the pump from ingesting air.

8. Replace the Check Valve

Check valves prevent water pumped into the discharge pipe from flowing back out once the pump is shut off. Older sump pumps use a basic swing check valve that works well enough but can cause gurgling noises due to uneven water flow. In many cases, these valves can create water hammering noises that can disturb your family and guests.

Old check valves can also fail due to debris buildup. As gunk collects around the check valve, it could prevent the valve from closing properly. The end result is water that keeps flowing back down the pipe.

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If your discharge line uses a swing check valve, replace it with a spring-loaded check valve. Not only does the latter function more quietly, but it’s also more reliable than the former. One of the best is the [amazon link=”B00JFF205Y” title=”Campbell CLR1.5″], featuring a fast closing 316 SST spring-loaded flap.

When installing your new check valve, make sure it’s properly oriented so that it functions correctly. The valve opening should always point away from the sump pump, not towards it.

9. Replace an Old Sump Pump

Consider this step as a last resort if you’ve tried all of the above tips. Sometimes, there’s not much you can do for a sump pump that’s on its last legs, especially when it’s an older model that’s outdated by today’s standards.

Upgrading to a more modern quiet sump pump has its benefits. Not only do newer pumps run quieter and smoother than ever, but they’re also more energy-efficient than previous models.

These days, modern sump pumps are made from plastic or cast-iron materials. Both types have their own set of upsides and drawbacks to consider:

  • Plastic sump pumps are more economical to purchase, but they’re not as robust as their cast-iron counterparts. Most pumps of this type also feature plastic impellers that are more prone to damage. These pumps are also a bit noisier than comparable cast-iron units.
  • Cast-iron sump pumps cost more, but they’re also more robust and longer-lived than plastic sump pumps. These units also offer quieter operations than their plastic counterparts.

Regardless of which type you choose, make sure you choose one that features a self-lubricating motor. This will save you additional maintenance, plus it ensures your sump pump runs quietly.

10. Regular Maintenance!

Yearly maintenance is a must if you want to prevent a noisy sump pump in the first place. Here are a few things you can do to keep your pump in great shape:

  • Check the power cord and make sure it’s not damaged in any way. Make sure the pump is properly plugged into a nearby power outlet.
  • Clean the pump inlet screen regularly to keep gunk and debris buildup at bay.
  • Test the sump pump every three to four months. This is as simple as dumping a bucket of water into the sump pit.
  • Remove the sump pump and clean it on a yearly basis. It’s also a great time to thoroughly inspect the pump for signs of wear, corrosion, and damage.
  • Check the condition of the discharge pipe both inside and outside your basement/crawl space. Make sure the pipe drains fully and check for any residual water that could freeze during cold weather.
Tom Davidson

I'm a Design Engineer, husband, and Dad to two. I have a taste for building, playing bad golf, and tackling all kinds of home improvement projects. Read more about the SPT Team.

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