Sump Pump Noises: What They Mean

Originally published 6/4/19, updated 2/20/20.

It’s most obvious at night. When everyone is in bed, the electronics are off, and it’s finally quiet. You’re relaxed, drifting in that lovely space between awake and asleep, when you hear it. A noise from the basement or crawl space, that sounds like something isn’t working properly. And just like that! Your peace is ruined, you’re wide awake, and your brain is in motion. You’re trying to determine what the noise is, what it means, if you need to fix something… How do you find out? Who can you ask?

Acculevel has been waterproofing basements and crawl spaces since 1996, and has installed thousands of sump pumps. We service the systems that we install and are experienced with the various noises and problems that can arise.

This article is for homeowners who have installed their own pump, or are researching the problems with sump pumps. We’ve compiled a list of the three most common sounds that can frustrate you. Our goal is to help you understand what is causing those noises and what you can do about it.

The Basics: What is a Sump Pump?

A sump pump is an appliance installed in a basement or crawl space, specifically meant to expel rainwater that seeps into the home. They are generally installed in conjunction with a water drainage system that collects and directs the water to the sump pump. The drainage empties into a “pit” in an opening in the floor that houses the pump.

There are three types of sump pumps: submersible, pedestal, and water-powered.

Water-powered sump pumps do not have a motor. This means that you don’t have to worry about a motor burning out or failing. However, they are the weakest type and we don’t recommend them in locations with moderate to severe basement flooding.
A pedestal sump pump does have a motor, but is installed above the waterline. This makes it easier to maintain, and will likely not wear out as quickly as a submersible. That being said, pedestal motors tend to be noisier than submersible because there is no water surrounding it to muffle the sound.
A submersible sump pump has a motor located under the water level. This means it’s in direct contact with moisture, so it’s more likely to wear out or rust than a pedestal pump. But it is the quieter option and the most commonly used type.

Why Is My Sump Pump Making a Noise?

Without audio samples, noises can be difficult to diagnose. But we’re going to do our best!

Is it a “thunk” that you’re hearing? Does it occur whenever the sump pump turns on or off? It may sound like someone is hitting a pipe with a hammer. This noise is loud enough to startle you, especially at night when your home is quiet. This most likely stems from the check valve on the sump pump. The check valve opens when water runs past it and closes when the water is gone. Like a door, this opening and closing can make noises. An easy way to reduce or eliminate this thunk is to replace the valve with a “silent check valve” available at home improvement stores.
Do you hear a loud rumbling motor sound? This usually sounds similar to a car engine idling roughly. These noises are most common in older sump pumps. You could try installing a rubber stopper to the pump if it’s vibrating against the wall of the pit. If that isn’t the cause, you may try lubricating the motor. If neither of these things works, the best solution to stop the sounds is to replace the sump pump.
Are you hearing clanging or rattling from the pipes? The movement of water through the pipes may cause them to vibrate against the side of the pit or wall. You can reduce those noises with a layer of insulation wrapped around the pipes, assuming they are above water.
Is it an electronic beeping sound? This is probably the alarm for the sump pump or battery backup system (if you have one installed). There are several possible explanations, but all of them mean you should investigate the alarm. This beeping means that the pump is not coming on, not working fast enough, or that the battery backup is almost out of charge. You should evaluate the power source(s) for the cause of the issue.

SAFETY TIP: Do not plug your sump pump into an extension cord. There should be a designated outlet installed nearby, so the pump can be plugged in directly. As with all electrical appliances, you should always unplug the pump before working on it.

Is the Sump Pump Enough to Solve Your Problems?

Most homes with a basement or crawl space need a sump pump, even if it’s only during the spring rains. But sometimes that may not be enough to keep your basement or crawl space clean and dry. If there is water pooling in some areas, if you see signs of decay in the wooden flooring system, or smell musty odors that indicate mold, you may need a more in-depth solution.

If you’re not sure what symptoms you have, or if they’re linked to foundation or basement issues, please use our free symptom checker. We designed this for homeowners to use as a diagnostics tool.

Do You Need Foundation Repairs or Additional Waterproofing Services?

If you live in Indiana or the surrounding states, contact Acculevel. You can request a free estimate, and we will schedule an appointment with one of our experienced project managers. He or she will evaluate your home and recommend the best course of action for you, to keep your home strong and healthy for years to come.

If you are having trouble managing the water in your basement, or need a new sump pump, we would be happy to help! The water drainage systems that we install are warrantied for the life of your home, and the sump pumps we install are warrantied for 5 years. We service all of our own installation work; none of our service calls are subcontracted to another vendor.

If you don’t live in our service area, you should find an experienced local foundation company, and make an appointment. Before you sign a contract for any service, you should always verify the company is reputable, insured, and accredited by the Better Business Bureau.