How to Quiet a Sump Pump: The Only Guide You Need

Every time it rains and every spring does the incessant gurgle of water, vibration and rattle of pipes, and thunk of the check valve echo through your house? Even though you’re trying to sleep two stories above it, you still hear it! Ever wondered how to quiet a sump pump?

How to quiet a sump pump. Ensure the pipes are secure so they won’t vibrate or thump. Adjust the float level to keep the intake valve covered with water to stop the sucking noise. Replace the check valve with a spring loaded one to quiet the gurgling. And then install an insulated cover over the sump pump and hole.

A sump pump is a necessary part of many homes. However, it doesn’t have to disrupt sleep and conversations. In this article I’ll discuss sump pump noises, their possible causes, and how to quiet those sounds. My goal is to provide you with the only guide you need to quiet a sump pump.

If you are tired of repairing the old one, and just need to replace it ,please see our article Best Quiet Sump Pump of 2023.

 

What Does a Sump Pump Sound Like

The sump pump system in each home has similar components, but may be configured differently, resulting in different noises. Here are some of the different noises that can be experienced with a sump pump system:

Motor Noise

There may be a “click” every time the motor turns on or off. Some motors hum and others whir at different volumes. The age, condition, and quality of the pump also contributes to the noise. However, if they squeal or screech, they should be replaced.

Vibration Noise

Water pumped through discharge pipes can cause them to vibrate and rattle. It may also make a clang as the pipe bangs against the sump well side, bottom, or lid.

Loud Banging Noise

The air being forced out of discharge pipes by water can cause a loud bang or water hammer. It often occurs as water is compressed through the pipe, and again when it suddenly stops. It can cause a pressure wave that reverberates through the discharge system.

Check Valve Noise

Check valves can clunk or bang as they open or close, or whistle and hum if debris gets caught in them.

Humming

A hum that isn’t the result of the motor can be caused by debris stuck in the intake or discharge pipe.

Gurgling

Water flowing through pipes can cause a gurgling noise. It can be the result of the check valve or lack of a check valve as water flows back into the sump pit from the discharge pipe.

Knocking

As the pump starts up and begins to push water through the pipe, the force of the flow can cause the pipe to knock against joists, walls, or the sump housing. It may also be the check valve banging open or closed like a door.

Clunking

Clunking can occur as the pump starts up and the torque causes the pipes to hit the pit wall or cover, or another structural piece. The same noise can occur when the pump stops. The check valve can also clunk when it opens or closes.

Common Causes of Sump Pump Noise

1. Poor Sump Pump Design

Sump pumps come in different designs and price points. Those made of light material will produce more noise than cast-iron pumps. Self-lubricating pumps will require less maintenance and produce less noise too. The motor drives an impeller which draws water from the pit into it and up the discharge pipe.

Pedestal Pump

The pedestal pump is inexpensive, and one of the noisiest pumps as the motor sits above the pit, allowing its noise to travel easily through the house. The motor is mounted on a long pipe, and the suction foot is at the bottom of the pipe in the pit. A float operates the on-off switch. 

It is a high capacity pump but is prone to burn-out. Plus, it tends to wander around the pit, causing the float to get trapped.

It can also rattle and knock against the pit sides. The pit often has no lid, so moisture and odors can permeate the room and building.

Submersible Pumps

Submersible pump motors are housed within the sump pit and often are muffled by water and the pit lid. The pump is immersed in the water, which cools it, helping to prevent burn-out, so it lasts longer.

The pumps are more expensive than a pedestal and made of a heavy cast-iron, so they wander less, making them quieter.

Floor Sucker Pumps

Floor suckers sit on the floor and remove water already in the basement or crawlspace. It requires a minimum of 1/8” of water on the floor to work. They don’t need a sump pit or permanent discharge pipes, so they can be plugged in when and where required. They are less expensive than other options. Unfortunately, they can block easily and are prone to overheating as the water level drops.

Water-Powered Pumps

Pumps powered by water pressure require consistent water pressure, like your town water to operate. They use 3 to 5-gallons of water to remove 1-gallon from the sump pit. The low volume pumps don’t use electricity and are long-lasting, but may not be practical in many areas.

2. Pump Location in the Sump Pit

The sump pump vibrates during operation. It should be located near the center of the pit base to prevent it from knocking and vibrating against the pit sides. The vibration can echo through the foundation and walls otherwise.

3. Pump Materials and Condition

Cheaply made metal and plastic pumps are noisier than heavy cast-iron pumps. Older pumps may also be noisier too. The screen that protects the impeller from debris should be of a non-corrosive material, as should the impeller parts. Debris and rust can cause noise. The float activator or pressure sensor turns the motor on-off and should also be of a material that won’t corrode or break.  Pumps that are corroded or produce a lot of heat should be replaced.

4. The Sump Pit Is Not Covered

An uncovered sump pit allows debris, toys, and even children to fall in, which can cause damage to the sump pump system and unexpected noises.  It also can add a damp smell or other odors to your home.

5. Motor Noise

Pedestal and submersible pump motors make different sounds. Some motors are self-lubricating, and others aren’t, which adds to the noise. Additionally, poorly maintained or older motors will be louder.

6. Vibrations Of The Discharge Pipe

Water flowing through discharge pipes can cause them to vibrate and bang against the sump pit sides and lid, or the house walls or joists.  ABS or plastic pipes will flex more than metal so that it may be noisier too.

7. Poor Design of the Discharge Lines

How the discharge pipes are configured and secured contributes to the noise. Two 45° angles are better than a 90°. Water will make more noise as it is forced through the 90° bend. The further the discharge pipe travels inside the house, the more noise it produces. Pipes without a check valve produce gurgling noise. However, a swing check valve can gurgle, clunk, and even whistle. 

How to Quiet a Sump Pump

1. Identify What Kind of Noise Well Pump Is Making

There are different ways the noises from the sump pump system can be quieted. The first step is to identify the type of noise or noises it makes. Determining where the noise is coming from may make it easier to address too.

Loud vibrations are caused as the water flows through the discharge pipes. A bang may be the check valve opening or closing. Knocking or thumping could be the discharge pipe flexing, or contacting the pump lid, pit sides, or structural members of the building. A click is usually the pump switch echoing when the pump cycles on or off. Other noises could be caused by debris, a failing pump motor, or a check valve leaking.

2. Seal and Insulate Sump Pit

The sump pit should be fitted with a removable insulated cover that fits tightly. The lid decreases noise and keeps debris, pets, or children from falling into the hole. The tight fit helps prevent rattle and helps keep pedestal pumps from wandering.  Adding rubber grommets to seal around the pipe and cable holes will stop knocking or thumping as the pump cycles on and off.

3. Secure Drain Lines

ABS and plastic pipes will flex and vibrate with water pressure, and metal pipes will vibrate. Discharge pipes should be fastened to the wall and joists where possible to reduce vibration.

Wrapping them in foam insulation wherever they contact structural members will also decrease noise. Shortening the run of discharge pipe within the home, and replace 90° turns with two 45°s will help too.

4. Replace Check Valve

Most sump pump systems have a one-way check valve to prevent water flowing back into the pit when the pump shuts off. The backpressure when the pump shuts off can cause the valve to bang shut. The valve may gurgle or whistle if it doesn’t close properly due to debris, age, or damage.

If there isn’t a valve, or it fails, the suction caused by the backflow when the pump stops will cause all the water in the drainpipe to rattle and whoosh back into the pit. This not only causes noise but can damage the impeller and will make the pump cycle more frequently. Install or replace the existing valve with a spring-loaded “silent” check valve. It will eliminate the bang or clunk as the valve opens or closes, and also prevent water from pouring back into the pit.

5. Adjust the Pump Switch

How often a sump pump cycles on and off, and how long it runs is determined by the pump switch. It is best to refer to the owner’s manual. Most sump pumps have a float activated switch or a pressure switch. Submersible pumps are under the water when the switch activates, so noise is muffled. A pedestal pump, however, is above the pit, which makes the switching noise more noticeable.

A pump with a vertical post-float activated switch should have an adjustment screw or nut that controls when the pump turns on and off. Adjusting the float to go higher in the pit increases the water level, so the pump cycles less frequently, but runs longer.

A tethered switch has a float on a cord that activates the pump. As it floats into an upright vertical position, a steel ball or mercury trips the switch, it shuts down when it drops into a downward position. Adjusting the length of the tether will change when the pump starts or stops.

Adjusting a pressure or diaphragm switch is more difficult, and may not be possible on some models. The power cord for the pump piggybacks on the pressure switch plug. The pressure switch is triggered by water pressure against the diaphragm, which then powers the pump. The switch is often mounted low on the pump housing and may be moveable for adjustment. It should be positioned, so the pump doesn’t run dry and burn out.

6. Install A Quiet Sump Pump

Sump pumps range between 1/3HP and 1HP; the greater horsepower is often noisier. High-quality pumps make less noise than inexpensive pumps, and a submersible pump is quieter than a pedestal one. Cast iron vacuum-sealed self-lubricating submersible pumps are a quiet choice.

Sump Pump Maintenance 

A sump pump hides away in a dark corner of the basement and is often forgotten until it suddenly turns on. Many people rely on the noise to let them know it is working, and if you have a sump pump, you want it in working condition. However, maintaining your sump pump is important, so you don’t experience a basement flood.

Maintenance is important, even if there are no flooding concerns. Here are some things you can do every other month to make sure your sump pump is ready when needed.

• Make sure the power cord is plugged in.
• Ensure the receptacle is live.
• Make sure the pump base is 8-inches from the pit sides.
• Observe that the tethered float is free to move, or that the vertical post-float moves freely.
• Check for and remove any debris in the hole.

Once a year, the pump should be removed and cleaned. Check the owner’s manual for parts that need to be lubricated, and do so.

• Examine the pump for rust that may interfere with operation.
• Thoroughly clean the sump pump and pit.
• Clean the screen that protects the impeller.
• Return the pump to the sump pit, and reconnect pipes and power.
• Pour enough water into the pit, so the float or pressure switch activates the pump and discharges the water.

The off-season is a good time to fix sump pumps, drain pipes, check valves, and to address noise concerns. It is also a good idea to install a battery back-up sump pump, just to be safe.

Conclusion

A sump pump is an essential part of many homes’ structural stability. It protects the foundation, keeps the basement or crawl space dry, and allows homeowners to breathe easier during wet seasons. Wrapping and securing the discharge pipes, installing a spring-loaded check, adjusting the float level, and tightly covering the pit opening are some ways to quiet a sump pump. 

My goal was to put together the only guide you need to quiet a sump pump. I hope you agree and found the guide informative and helpful. If you do, share it with others. Your comments and suggestions are appreciated.

 
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