Flooding anywhere is a nightmare, and as rain levels increase year over year, home floods are unfortunately becoming much more common. If you have a basement, whether it's finished or just bare studs, or live in an area that gets heavier rainfall, you know firsthand how difficult it can be to protect your home from unrelenting dampness and water. A sump pump is your home's first line of defense against flood damage, water damage, and sitting water. If you're renting or buying, the home likely already has one, but it's important to know how they work and what they do in case any problems arise.
A sump pump can be beneficial for protecting your home even if you live in a desert. "A sump pump collects excess water that can build up because of various factors, including heavy rain, but also melting snow or groundwater," says Ryan Maskell, managing director at Mask Plumbing Solutions. "It directs the excess water away from the foundation of the building to a drainage area elsewhere. This, therefore, prevents any water damage that may have occurred otherwise."
Ahead, Maskell and two more plumbing experts—Jason Jones, owner of ATX Epoxy Floors, and Josh Mitchell, plumbing technician and founder of Plumbing Lab— explain what is a sump pump, why one might be necessary for your home, and what to look for when buying one.
What Is a Sump Pump and How Does it Work?
A sump pump is a plumbing device that moves water from inside your home's basement to the outdoors, where it's supposed to be. A well-maintained sump pumps can help you avoid thousands of dollars in structural damage and repairs, not to mention protect your home and personal belongings.
A sump is a constructed pit or basin—a hole, essentially—that is installed below the main surface of your flooring. The pump itself sits inside this pit and senses both water pressure and water levels in order to know when to jump into action. When the water in the hole gets too high, the sump automatically starts to siphon water from inside your basement away from your property using what's called a discharge line. This line connects the pump to the designated drainage area—a place that's determined by the building code requirements where you live and the plumbing pro you hire to install it.
A sump pump is also beneficial for preventing mold, mildew, and foundation damage. "By keeping the basement dry, sump pumps discourage the growth of mold and mildew, which thrive in moist environments," Mitchell says. These pesky growths can pose serious health risks. Plus, prolonged exposure to water can weaken your home's foundation, he adds. A sump pump keeps water at bay, preserving your home's structural integrity.
Types of Sump Pumps
Submersible
These sump pumps contain the pump and motor in one unit. Because they're fully submerged in the water basin, these units are often smaller and quieter than other kinds (like pedestal units; more on those in a minute) and save space in your basement. Despite their compact size, they're the best option for homes with major flooding concerns.
Pedestal
Pedestal sump pumps consist of separate motor and pump components. The motor sits above the basin on a sort of pedestal, while the pump is deep in the basin and connected via hose. Because the motor isn't submerged, it often lasts longer than the motors in other types of sump pumps. This type is also more accessible for maintenance and upkeep.
Battery-Operated Backup
Backup sump pumps are great for homeowners who want a bit of extra security and protection from water damage. A battery backup with a float switch allows your sump pump to operate even if your power goes out during a storm—in other words, when you need it the most. The float switch gets triggered when water levels are too high, sending your sump pump's battery into action.
Water-Powered Backup
Water-powered backup sump pumps clear water from your basement and basin through an increase in water pressure. The advantage of a water-powered system is there's no need to monitor the backup or replace any batteries. Some cities don't allow water-powered pumps because of their high water usage, though. Check your municipality's water-usage guidelines to be sure.
Types of Switches
Diaphragm Switch
This is the most common type of sump pump switch since it rarely gets stuck in the on or off position.
Pressure Switch
This type triggers the pump once the water pressure reaches a certain level.
Float Switch
As mentioned above, a float switch equips a battery-operated backup sump pump. It sits on top of the water and turns on the pump as the water level rises.
Electronic Switch
An electric switch is dependent on charged probes to sense the water pressure in the basin.
When Should I Replace My Sump Pump?
Between equipment age, amount of use, level of corrosion, and the actual sound of the motor, there are a number of signs to look for when deciding whether to replace your sump pump. A good rule of thumb is to replace your unit every seven to 10 years, depending on amount of use. "Watch for signs of wear and tear," suggests Jones. "If it's making weird noises, cycling on and off too frequently, or just not pumping like it used to, it might be time for a replacement." He adds, "Also, if it's hitting the 10-year mark, it's worth considering an upgrade before it decides to retire on its own terms."
If you notice your sump pump running continuously, there may be an issue with the switch sensor. If it takes too long to empty the basin, it's probably a sign that the unit no longer has the horsepower required to function properly.
Toward the end of your sump pump’s life cycle, you may start to hear a roaring sound from the motor. If you can hear the rattling or clanging of your sump pump upstairs in your house, it’s a sign the motor is nearing failure. Loud noise may also indicate damage or improper installation of the sump pump's discharge lines. As always, consult a professional prior to making any major changes.
What to Know When Buying a Sump Pump
Cost
Generally, a sump pump will run you between $100 and $500 for residential units, though prices vary based on size, horsepower, and flow rate. However, installation will tack on another $600 to $3,000 depending on the extent of work needed. All in, adding a sump pump will likely cost between $700 and $3,500 total.
Horsepower
An average household can function well with a sump pump that has a flow rate (water removal rate) of 1,800 to 2,200 gallons per hour. Common motor sizes include ¼ horsepower to 1 horsepower. If you live in an area that's prone to flooding, opt for a unit that has around ½ hp that can expel as many as 5,000 gallons per hour.
Water Alarm
Another cost associated with sump pumps is the option to add a water alarm. These monitor the water level and will alert you and your household if the sump pump starts to fail or if the water gets too high.
Kate McGregor is House Beautiful's Digital Editor, writing in-depth , design inspiration stories, and . With over five years of experience writing commerce and search-optimized content for brands like Domino, Real Simple, and Architectural Digest’s Clever, Kate has developed a passion for uncovering the personal stories that often lie behind the inspiration for people’s spaces. She previously worked as the assistant market editor at ELLE Decor where she identified top products and brands in the industry and interviewed emerging designers about their thoughts on the latest . Kate holds a bachelor’s degree from Belmont University. When not researching the specificities of begonia plant care, you can find Kate scouring vintage markets for the ideal wrought-iron chair, knitting yet another cardigan, or reading historical nonfiction.
