Why Your Basement Still Flooded With a Sump Pump

Keep your head above water when your sump pump fails

A living room with a fireplace located in the basement of a house
Photo: Andrea Rugg /The Image Bank / Getty Images
A living room with a fireplace located in the basement of a house
Photo: Andrea Rugg /The Image Bank / Getty Images
Highlights
  • A basement with a sump pump can still flood for many reasons.

  • Sump pumps can fail due to a broken part, overuse, or lack of power.

  • There are ways to mitigate basement flooding to assist your sump pump.

  • Test your sump pump regularly to ensure it works in an emergency.

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When left unchecked, water damage in your home can be permanent, even down in your basement. Whether you have an unfinished basement packed with boxed-up memories or a cozy finished room for watching movies, the chances of your basement flooding depend on your sump pump (more on sump pumps below). Check out what causes basement flooding, immediate steps to mitigate damage, and how to prevent flooding in the future.

What Is a Basement Sump Pump?

Before we get into the common causes, let’s discuss how a sump pump works in your basement. A sump pump sits in a pre-dug well at the lowest point of your basement floor. If the water reaches a certain level, the sump pumps kick on and sends the water through a series of pipes to a drainage area. 

Sump pumps are designed to prevent groundwater from entering your home, but they’re also great for dealing with busted pipes or a broken washing machine. A sump pump can save your basement from permanent damage during a flood.

What Causes a Sump Pump to Fail?

Granted that your sump pump is properly installed and has the power it needs to function, it can still fail. Just like any other appliance in your home, electric and mechanical parts can become clogged, stuck, or disconnected as the rush of water comes and goes. Some of the most common culprits of a failed sump pump include:

  • The float switch will not activate because it is blocked by a buildup or an object in the tank.

  • The float switch is in the wrong position and needs to be adjusted according to the owner's manual.

  • The impeller blades are worn down, blocked, or clogged.

  • Something is blocking and clogging the discharge line.

  • Your discharge line has a leak or has become disconnected from the pump.

  • The sump pump motor has burned out due to a clog or poor discharge pipe design.

Reasons Your Basement Flooded With a Sump Pump

So, what happens when your sump pump is chugging away, but your basement is still full of water? In most cases, your pump simply cannot keep up with the amount of water flooding the room. You'll need to go to the source and either check if you can stop the flow before it reaches your basement or install additional sump pumps capable of taking on the extra water. 

1. Clogged Gutters

Gutters deposit water away from your house. A clogged gutter can overflow and allow water to pool around your home and seep into the basement.

The next time it rains, walk around your home to see if you notice any issues with your gutters. You can clean your gutters on your own or reach out to a professional who can evaluate your gutters, repair them as needed, or suggest a different placement to reduce your flooding risk.

2. Broken Downspouts

Downspouts deposit water away from your home’s foundation and should be at least six feet away from your basement (some professionals even recommend 10 feet). Broken or missing downspouts can lead to foundation drainage issues such as cracks and holes.

You can easily replace a missing downspout on your own. But if you sense the issue has more to do with design, a professional can help you effectively re-route water away from your home.

3. Poor Basement Sealing

A pro must seal the basement properly to prevent flooding. If the contractors didn't waterproof your basement during construction or sealed it incorrectly, water can seep into your basement over time. This will happen faster in areas prone to heavy rain or lots of snow. Thankfully, you can learn how to waterproof your basement on your own through a variety of methods.

4. Record-Breaking Water Events

A finished laundry room in the basement of a house
Andrea Rugg/The Image Bank via Getty Images

Your sump tank is likely sized for the average annual rainfall or snowfall in your location. When storms dump more water in less time than anticipated, it may be too much for your sump pump to handle. 

If you notice your pump struggles more often than not, it may be time to have an expert come and take a look. Most sump pumps last for about 10 years. Frequent failure to expel water fast enough from the tank could be a sign that you’re due for an upgrade.

5. Power Outage

Standard sump pumps can’t work without power. Whether a bad storm knocked out the electricity or a sudden power demand blew a fuse, a pump without a power source will fail. Luckily, there’s a simple solution (especially because power outages are common in flooding events).

Some models connect to a backup battery or work with the water pressure in your home in the event of a power outage. We always recommend installing a pump that will automatically switch over to battery power if the power goes out. Another recommendation is to have a backup generator for power outages. Just make sure you’re able to operate your generator safely (i.e., outdoors and at least 15 feet away from any open windows) to keep your pump working.

6. Overworked Pump

A small pump can often handle the same amount of water as a larger pump. However, a continuously overworked sump pump will have a shorter-than-expected lifespan. This could leave you without a functioning pump in the middle of an otherwise controllable disaster.

Sump Pump Not Working: How to Troubleshoot

If your sump pump isn’t keeping your basement dry, and you notice signs of basement water damage, you may need to troubleshoot to figure out what’s wrong. Check these things to diagnose the problem or call a local sump pump repair pro to fix the issue:

  • Verify that there’s power going to the sump pump.

  • Check that the pump is properly connected to the drainage system.

  • Assess the check valve and discharge line.

  • Look for clogs or debris that could be interfering with the pump’s operation.

  • In cold weather, look for signs that the pump has frozen.

  • Ensure your sump pump is large enough and has enough capacity to handle the amount of water. Upgrading to a larger, more powerful pump may solve the problem.

Ways to Prevent Your Sump Pump From Failing

Your sump pump is one of those home appliances that really needs to work when the time comes. The best way to prevent a sump pump failure is to test it regularly. You can either do this by unplugging it and plugging it back in—therefore causing it to reset and kick on—or by filling the tank without enough water to activate the pump.

You can also avoid a critical sump pump failure by:

  • Installing a backup generator for when the power goes out during a storm.

  • Purchasing a sump pump with a backup power alternative. 

  • Installing two sump pumps in your basement to avoid motor burnout during a flood.

  • Contacting a local sump pump installation team to ensure the pump and tank are installed properly.

  • Protecting the sump pump area from fallen debris, mold, and mildew.

What to Do if Your Basement Floods

Once you discover a flooded basement, you’ll need to act fast to prevent further damage. First, remove as much water as possible (if you can safely do so) and run a fan to dry out water damage. If it is unsafe to enter your basement due to the amount of water, live electrical fixtures, or any other reason, skip right to calling the pros.

Hire a water damage restoration pro to return your basement to its pre-flood condition. A pro can determine the class of water damage, whether you need water mitigation or remediation, and the necessary repair and restoration steps to get your basement back to normal. Water damage restoration costs an average of $1,400 to $6,300, depending on the damage's extent.

Frequently Asked Questions

A sump pump will drain a flooded basement if it has a horsepower strong enough to remove the water faster than it is entering the room. If you have the wrong type or size of sump pump installed–or if your sump pump has failed–you may need to take additional steps to stop the flow of water or remove it manually.

In most cases, standard homeowners insurance will not cover sump pump failure, even during a storm. However, some plans will cover damage depending on the source of the water and if the flooding came from a sudden unexpected event, such as a burst pipe not caused by negligence. You will likely need to purchase additional water damage and sump pump insurance to prepare for the event your sump pump cannot do the job. 

Sump pump replacement costs between $300 and $750 depending on the size and style of the pump. However, the price will fall on the lower end of the spectrum if you do not need a new tank installed, or if you only need a minor part of the pump repaired.

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