What Does a Sump Pump Sound Like? (8 Sounds)

When it comes to home maintenance, few things are as essential as keeping your basement dry. A sump pump plays a pivotal role in safeguarding your underground space from the wrath of water intrusion. But have you ever wondered, “What does a sump pump sound like, and should I be concerned about it?”

Under normal operation, your sump pump will produce a low continuous hum. But when you notice it making loud and weird noises (commonly described as sounding like a washing machine), it’s time for inspection and repair. A grinding or rattling noise indicates something is wrong with the fan or impeller.

In this article, we shall look at some of the most common noises a sump pump makes and the best troubleshooting methods to fix them.

The Significance of Sump Pump Sounds

Why should you care about the sounds your sump pump makes? The answer is simple: these sounds serve as an early warning system. By paying attention to the sump pump noises, you can identify potential problems before they escalate into costly disasters.

Consider these sounds as how your sump pump communicates with you, letting you know if everything is fine or needs attention. Ignoring these sounds is like disregarding your sump pump lifeline for your home’s safety.

Nonetheless, a number of things can contribute to the pump system producing more noise than usual. The following are a few of the top common causes:

• The type of pump 
• How well-ventilated the pump is
• The quantity of lubricant used in the pump
• The pump’s placement in relation to the sump basin

1. Sump Pump Making Clanging Sounds

A small metallic clanging is normal when the sump pump initially starts up. That clanging noise is the sound of water striking the piping that sends it outside. That clang, however, ought to subside after a couple of minutes. If the sump pump in your basement continually creates a clanging noise, it could be because the pump was not correctly installed, and people responsible were forced to reroute the pipes to make it work, resulting in an annoying persistent clang. In most cases, insulation of the pipe fixes the problem.

2. Sump Pump Loud Motor Noise

Motors are unavoidably loud. However, if the noise from the sump pump motor sounds excessive, it’s possible that it’s an old system and the motor is not broken—it’s simply noisy. Examine the material construction of your pump. If it’s made of plastic or PVC, it’s probably an older pump. Replacing it will help solve the loud motor problem.

Pumps are classified as “submersible” or “pedestal.” Since the motor of a submersible pump is located inside the pit—often below ground and covered by a cap or cover—they are quieter.  Pedestal pumps are noisier because they are usually installed around 24 inches above the floor.

Sump pumps made of PVC or plastic are noisier than cast-iron pumps. Modern pumps have self-lubricating motors and operate quieter.

Choose a replacement type that allows the motor to be placed beneath the sump basin and has cast-iron architecture and self-lubrication. The new unit should have a completely insulated top or covering to reduce noise levels.

• How to make a sump pump quieter
• Sump pump making gurgling noise
• Top 11 quietest sump pump for basements

3. Sump Pump Making Gurgling Noise

Gurgling sounds are often generated as the pump cycles, and water runs back down the output pipe.

Use a spring-loaded check valve instead of the conventional swing check valve to prevent gurgling. This kind of valve allows water to pass through the pipework more efficiently, which lessens gurgling.

Another method for reducing gurgling noises is changing the pump switch to ensure it turns off before the basin is empty. When the sump pit is empty, the pump produces a sound identical to a person drinking soda through a straw.

4. Sump Pump Vibrating

You might hear a vibrating sound as the drainage pump moves water around the rest of the plumbing when the discharge pipe is connected to the sewage pipes. It is possible to reduce the noise made by pipes while water flows through them. Just put foam rubber insulation around the pipes. However, in certain parts of the country, the law demands that the pipes that discharge wastewater carry water entirely to the outside rather than through the sewer lines. You can engage a contractor to relocate the discharge line, eliminating vibrating noise and guaranteeing the sump system meets local regulations.

5. Continuously Running Pump

If you notice the sump pump running constantly, it is most probable that the pump is not the ideal size for your basement—oversized and undersized pumps present issues. Ideally, the pump should be the same size as the basin in which it is mounted.

For instance, a large pump placed in a tiny basin will pump more water than the pit can hold. You’ll have to cope with the loud, annoying noise it produces while running, and the strained drain pump will eventually run without water and break down.

6. Making Humming Sounds

Slight humming sounds originating from a sump pump are typically within regular operation. Nevertheless, if you notice an unusual increase in the volume of the humming or if the pump seems to have trouble moving water, it’s a sign that investigation is warranted.

Begin by examining the vent hole for potential obstructions and removing them if necessary. If this doesn’t resolve the issue, the problem might lie with a check valve that has become stuck. Ensure the check valve is correctly oriented towards the “Discharge” position.

In cold weather conditions, frozen discharge pipes are another potential factor to consider. You can cautiously employ a space heater to thaw any ice inside the pipes. However, if this approach proves ineffective, the root cause could be a malfunctioning impeller, which is the component responsible for drawing water into the pump.

In such a scenario, conducting internal cleaning of the impeller may be necessary to restore the pump’s functionality.

Sump Pump Humming but Not Pumping

A sump pumps faint buzzing is often normal. This is a common sound made by the pump, however if the hum is continuous, the system could be operating without moving any water. A common reason of this is the absence of a relief hole between the check valve and the pumo, which will result in an air lock in the system. Drill a 1/16 inch hole at a downward angle into the pipe so that water flows into the pit between the pump and valve.

An obstruction in the line, usually at the pump, could be another reason. This can be resolved by taking out the sump pump and its bottom plate, as well as removing the obstructions. If the problem doesn’t resolve, it’s highly recommended you involve a licensed plumber, as the problem is probably further down the line.

Humming can also signal that the pump’s electric motor has failed, necessitating the replacement of the unit.

7. Sump Pump Check Valve Noise

A standard check valve, also known as a non-return valve or one-way valve, is a mechanical device designed to allow fluid (such as liquid or gas) to flow in one direction while preventing it from flowing in the opposite direction. It is typically used to ensure that fluids move in a specific direction and do not backflow.

If you happen to notice a loud noise each time the sump pump stops, then you are likely to have a Standard Check Valve fitted. That sound is caused by the check valve closing, which results into a slamming sound as water movement in the pump’s discharge pipe reverses when the pump stops.

Unfortunately, you can only get rid of this type of noise by replacing the standard check valve with a quiet check valve.

The Quiet Check Valve has all of the characteristics of a regular check valve, plus a spring-loaded hinged flapper design that drives the flapper mechanism to close completely against water flow when the sump pump shuts down. This quick closing mechanism against pressure before any backflow occurs prevents water hammer noise.

8. Sump Pump Grinding Noise

If the sump pump in your basement produces a grinding noise, contact the nearest plumber to have the issue diagnosed. A malfunctioning impeller will typically produce a grinding sound. The sump pump’s impeller is in charge of sucking the water that finds its way into the basement. This is required for the sump pump to function properly. Even though the impeller might merely be clogged, it might still need to be changed. Contact your nearby plumber to identify and repair the problem.

Final Thoughts

In conclusion, understanding the sounds of a sump pump is essential for every homeowner who relies on this valuable piece of equipment to protect their basement from flooding. While sump pumps typically emit a distinct hum or vibration during normal operation, it’s crucial to pay attention to any unusual or excessive noises that may indicate a problem. Regular maintenance and occasional testing can help ensure that your sump pump is in good working condition, and if you ever hear anything out of the ordinary, it’s best to address the issue promptly to prevent potential water damage.

Remember that sump pump sounds can vary depending on the model, size, and age of the pump, as well as the specific conditions in your basement. Familiarizing yourself with the typical noises your sump pump makes will help you differentiate between normal operation and potential issues that may require professional attention.