Sump Pump Humming But Not Pumping: What To Do?

If you have a home with a basement, you know that it can get damp down there. To keep the basement dry, your sump pump should work properly and pump out water. But what do you do if it doesn't pump out water and makes a humming noise? We researched what this means and what you can do about it, and here's what we found.

It's normal if your sump pump makes a humming noise, but if it is louder than usual and doesn't pump out the water from your basement, you'll need to investigate further. You need to check your sump pump for possible scenarios that may be causing the issue, such as:

  • Clogged vent hole
  • Stuck check valve
  • Frozen pipes
  • Damaged impeller

Knowing where to check for problems can help eliminate the potential unnecessary cost that you'll incur if you are to call a professional. We go through each issue to help you determine solutions for your sump pump.

Household submersible pump with plastic housing, Sump Pump Humming But Not Pumping: What To Do?

Checking Your Sump Pump

Two household submersible pump with plastic housings on stone floor of courtyard

Water can accumulate in your basement for many reasons, which, if not addressed, can destroy your belongings or accumulate mold. This is why the sump pump is important. Beneath the basement floor is a basin where all the water is collected. Upon reaching a certain level, the sump pump siphons and expels the water from your home and into a drainage area.

If the sump pump working correctly, it may hum, but the sound level shouldn't be loud enough beyond the basement walls. However, a loud humming sound and a sump pump that doesn't take out the collected water from your basement will need to be checked before the problem becomes serious. Here are the possible causes:

Clogged Vent Hole

A sump pump in a home basement-plumbing repair

A vent hole, or a weeping hole, releases air pressure to prevent an airlock. An airlock happens when the pump's chamber gets filled with air instead of water from the basin, preventing it from pumping the water out. It may sound complicated, but a weeping hole is a simple hole drilled into the sump pump. If this is clogged, air can come in and cause an airlock. To fix that, clean the clogged vent hole to allow airflow.

Stuck Check Valve

A check valve is an apparatus that allows water to only flow one way. When water is expelled out of the discharge pipe, the check valve is there to stop it from flowing back into the basin. By doing this, the sump pump won't need to pump out the same batch of water constantly.

However, if your check valve gets stuck, the water from the discharging pipe will get back into the basin when your sump pump attempts to pump it out. Because of that, the sump pump will always try to throw out the same water from the basin, causing the motor to run and shortening its lifespan. If this happens, you may need to change your check valve.

Frozen Pipes

Discharge pipes can freeze in the winter or simply because the area is cold. The water inside the pipes can freeze, causing ice to form and preventing water from coming out when the sump pump works to expel the water. If this is the case, simply place a space heater carefully to melt the ice in the pipes.

Damaged impeller

If all else fails, then you may have a damaged impeller on your sump pump. The impeller is responsible for sucking the water out of the system when it's time to pump it out. If the issue is in the impeller, you may need to check its blades for any damage and replace it with new ones.

Other Possible Signs Of Problems

Apart from not pumping out water and having a loud hum, you may hear or smell certain things that signal that your sump pump may have a problem. Each of these is triggered by different things, which aren't necessarily a cause for worry, but it is important to determine what kind of signals you are hearing or smelling from your sump pump. This way, you know what to check for when they do happen.

draining water from structure, generally accomplished with a pump or suction


A grinding sound can mean the impeller is faulty or the debris is stuck. While the sump pump collects water into the basin, it can also collect debris, eventually finding its way to the impellers. You must clean out the debris and check the blades for damage.


If there's a banging sound, that may mean that the discharging pipe needs to be secure so it won't move and create the sound. To do this, you can use wires for fastening the pipes.


To address a gurgling sound coming from your sump pump, you can replace the spring of the check valve to help it work better. If that doesn't work, try the pump basin's automatic turnoff level and adjust it. Otherwise, you may need to call an expert to diagnose the problem.


Similar to the banging sound, the clanging noise you may hear from your sump pump isn't a cause for immediate worry. When your sump pump clangs, it's because of vibration. Clanging from the sump pump can be fixed by adjusting the position of the discharge pipe or wrapping it with insulation to lessen the noise.


If you smell something funky in your basement, you'll have to check the drain trap of the pump sump to see if it still has water. This water stops gas and sewage from entering, but it also evaporates. To prevent that unpleasant smell, simply refill the drain trap with water. You can also disinfect it with a bleach solution or scrub the walls of the drain trap.

Types of Sump Pumps

Residential sump pump during a summer snow storm in Colorado

Sump pumps come in four types that all serve the purpose of pumping out water from the basement, but have different ways of treatment. This can vary from the way it is placed or how it can operate. Depending on what you need, you'll need to know what kinds are out there to determine what's best for your home.

Submersible Sump Pump

As the name suggests, this sump pump usually has the pump and motor submerged into the basin as a single unit. Because of this, it doesn't take up space in your basement, works quieter than the others, and works well in areas with heavy flooding. While it is a more popular choice for homeowners, it also has a short lifespan due to the motor being submerged in water.

Take a look at this submersible sump pump on Amazon.

Pedestal Sump Pump

With this type of sump pump, the motor is located on top of a pedesta above the basin. Meanwhile, the pump is located in the basin. Unlike the submersible type, the pedestal sump pump has a longer lifespan since the motor is not submerged and can be better maintained. The downside of this type of sump pump is that it can be noisy and take up space.

Take a look at this pedestal sump pump on Amazon.

Battery-Operated Backup Sump Pump

If there's a blackout in your home, this type of sump pump can be useful as it has a battery backup to power it. You can imagine that this is helpful during a storm when there may be possible flooding in your basement, and you need your sump pump to expel water out of your home.

Take a look at this battery backup sump pump on Amazon.

Water-Powered Backup Sump Pump

As the name implies, this sump pump requires a significant volume of water to use as water pressure and clean the basin. This also means you don't have to check the batteries or backup. However, not all cities advise using this type of sump pump.

Final Thoughts

A sump pump with some water around it.

Your sump pump will usually make a humming noise, but if the humming is especially loud and the pump isn't pumping out water, it is not working as it should. You will need to check if it has a clogged vent hole, a stuck check valve, frozen pipes from the cold temperature, or a damaged impeller that needs to be replaced. If you checked all of these possible issues and the problem persists, you may want to call a professional to address the issue.

Here are some articles that can also help you:

Water Coming Up From Basement Floor—What To Do?

How To Hide Sewer Cleanout In Basement?

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