Sump pumps are a common fixture in homes nationwide. However, your basement may have what appears to be a second sump pump. This second pump is commonly found in finished basements near the washer and dryer. Even though it may look similar or even identical, this is an ejector pump. 

    But what are ejector pumps, and how do they differ from sump pumps?


    Sump Pumps

    Sump pumps are small water pumps available in either pedestal or submersible models. These pumps protect your basement from flooding caused by excess groundwater.

    Groundwater is water that accumulates in the soil and rock beneath the earth’s surface. Excess groundwater entering your basement can come from a high water table or heavy rains, causing water buildup around and under your home’s foundation. 

    It can also come from melting snow in spring — putting pressure on your basement walls and floor — as well as downspouts, gutters, and grading issues directing rainwater toward your home.

    This groundwater is generally cold and clear. However, flooding from excess groundwater can damage everything stored in your basement. If you don’t promptly clean it, it can also lead to mold, mildew, and rotten smells.

    How Sump Pumps Work

    A sump pump system consists of a basin or sump pit installed under the basement floor, at least two feet deep and the sump pump designed for water, connected to a discharge pipe. 

    The system also includes an interior or exterior drain tile system that feeds water from around the foundation into the sump pit and a float switch to trigger the pump on when water in the pit reaches a certain level.

    The float switch rises as water enters the drain tile and fills the sump basin. This triggers the sump pump to turn on and pump water out through the discharge pipe.

    The discharge pipe carries the water away from your house either to the lawn and landscaping, a dry well or drainage ditch, or a municipal storm sewer system. Diverting the water away from the home’s foundation helps prevent flooding.

    The float drops and turns off the pump as the water level decreases. This cycle repeats whenever excess groundwater enters the drainage system.

    Other Sump Pump Traits

    Proper installation is key for a sump pump system to work reliably. Specialized basement waterproofing contractors typically handle sump pump installation. They know the optimal placement and setup to keep your basement protected.

    Many sump pump models include a backup battery or secondary pump to operate during power outages. Since heavy rains and storms can cause both flooding and power loss, having a backup power source provides peace of mind that your pump keeps working even in a blackout.

    Routine maintenance is required to sustain sump pumps for their full life span. Maintenance needs increase in homes more prone to frequent water issues. Some common sump pump problems include:

    • A damaged float switch preventing the pump from turning on/off
    • Battery backup failing to activate during an outage
    • Pump burnout from constant cycling on/off
    • Sediment buildup causing clogged discharge pipes
    • The pump repeatedly turning on and off frequently

    Ejector Pumps

    While ejector pumps may look like sump pumps, they serve a different purpose — to pump out wastewater and sewage, not clear groundwater.

    Ejector pumps handle “black water” waste — water contaminated with bacteria, dirt, and organic matter from kitchen sinks, washing machines, showers, and toilets.

    Today’s Homeowner Tips

    You’ll typically find ejector pumps installed in finished basements to drain fixtures located below the main sewer line — including water from floor drains, washing machine discharge, sinks, full bathrooms, and any other sources of gray wastewater.

    How Ejector Pumps Work

    Ejector pumps have a holding basin collecting incoming wastewater, like a sump pump. But this basin is sealed and connected to a vent pipe releasing sewer gasses outside.

    When a connected fixture like a sink or toilet runs, the wastewater flows into and fills the sealed holding tank. Once it reaches a certain level, the pump activates to drain the tank into your home’s main sewer line.

    Most ejector pumps also include a grinder mechanism to grind up any solid waste added to the holding tank for clean pumping. An alarm float switch specifically triggers the grinder when enough solid waste accumulates.

    Traits of Ejector Pumps

    Ejector pumps are sometimes called sewage ejector, grinder, or slurry pumps. They handle “black water” waste, requiring careful cleaning if flooding occurs to avoid contamination.

    Unlike sump pumps, ejectors don’t require much routine maintenance. However, they can fail from solids clogging the mechanism or pump burnout from frequent use.

    Power outages are another concern since ejector pumps lack battery backups. Without power, wastewater can quickly back up and overflow the holding tank into your basement.

    Some common ejector pump problems:

    • Clogs from large solid objects like toys or wipes
    • Failure to activate, allowing the holding tank to overflow
    • Frequent cycling leading to premature pump failure
    • Inability to operate during power outages

    Choosing the Right Basement Pump

    For new construction or renovations, how do you choose whether to install a sump pump, ejector pump, or both? Look at these key factors:

    Install a sump pump system if your home is prone to basement flooding from groundwater, is in a region with a high water table, is at the bottom of a hillside, or is in a neighborhood with chronic water drainage issues.

    Add an ejector pump if your home has a finished basement with fixtures below the sewer line, has laundry drainage needs below ground level, has a basement bathroom or full kitchen, or has gray water drainage problems from tubs, sinks, etc.

    Having both pumps in your basement provides full protection in flood zones or chronically wet basements prone to water intrusion, for homes with below-grade bathroom fixtures and if you have a walk-out basement with one section below the sewer line. 

    Installing both systems also provides backup redundancy. If one pump fails, the other can prevent sewage backups or water flooding until repairs are made.


    So, Are Dual Pumps Worth the Cost?

    For many homeowners, having dual sump and ejector pump systems provides ideal protection and redundancy. But is the added cost of installing two pumps instead of one worthwhile?

    For homes highly vulnerable to basement flooding, dual pumps can certainly be a smart investment. Repairing extensive damage from groundwater or sewage backup can cost thousands, easily exceeding the price of a second pump system.

    Dual pumps also provide greater peace of mind. As one pump malfunctions, the second provides critical backup protection, minimizing the risk of a flooded basement.

    However, for homes with minimal flooding risks and no fixtures below the sewer line. The added cost of a redundant ejector system may not be fully justified.

    Ultimately, the value depends on your home’s unique needs and vulnerabilities. Dual-pump systems offer maximum protection but aren’t mandatory for all basements. Assess your specific flooding and drainage risks before deciding.

    Get Free Estimates From Professional Plumbers
    Match with a plumbing expert to help you with installation or repair.

    FAQs About Sump Pumps and Ejector Pumps

    Where are sump pumps typically installed?

    Sump pumps are installed under the lowest level of a home, usually the basement. The sump pit is dug beneath the concrete basement floor or slab.


    How often should sump pumps run?

    How often a sump pump runs depends on how much groundwater enters your home. During heavy rains, they may run frequently. In drier weather, they may only run every few days. Frequent short cycling generally indicates an issue.


    How long do sump pumps last?

    Most quality sump pumps typically last five to ten years with proper maintenance. Lower-end pumps may last only three to five years. Factors like frequent cycling can shorten life span.


    Can sump pumps handle sewage?

    No, sump pumps are designed only for clear groundwater. Sewage will damage the pump and create unsafe conditions. Only ejector pumps reliably handle wastewater drainage.


    How much does installing ejector pumps cost?

    Adding an ejector pump system to an existing home generally costs $2,000 to $4,500. New construction installation ranges from $1,500 to $3,000. The basin size, pump type, and complexity impact the overall costs.


    When should you repair or replace a sump pump?

    Signs like loud operation, short cycling, reduced pumping capacity, tripped breakers, musty smells, and flooding indicate a failing sump pump needs service or replacement.


    Can I install a sump pump myself?

    Installing a sump pump system requires digging, trenching, electrical work, and plumbing skills. Hiring a professional waterproofing contractor is strongly advised unless you have this expertise.


    How loud are ejector pumps?

    Ejector pumps are typically noisier than sump pumps, especially when grinding solids. But modern insulation around the tank and pump helps dampen noise. They are usually no louder than a washing machine.


    Should sump pumps run continuously?

    No, continuous operation indicates an issue like a stuck float or check valve failure. Contact a repair service if your sump pump runs non-stop without pausing.


    How often should backup batteries be replaced?

    You should replace backup sump pump batteries every three to five years to ensure they work when needed. Test them annually and replace them immediately if tests fail.


    Editorial Contributors
    avatar for Jonathon Jachura

    Jonathon Jachura

    Contributor

    Jonathon Jachura is a two-time homeowner with hands-on experience with HVAC, gutters, plumbing, lawn care, pest control, and other aspects of owning a home. He is passionate about home maintenance and finding the best services. His main goal is to educate others with crisp, concise descriptions that any homeowner can use. Jon uses his strong technical background to create engaging, easy-to-read, and informative guides. He does most of his home and lawn projects himself but hires professional companies for the “big things.” He knows what goes into finding the best service providers and contractors. Jon studied mechanical engineering at Purdue University in Indiana and worked in the HVAC industry for 12 years. Between his various home improvement projects, he enjoys the outdoors, a good cup of coffee, and spending time with his family.

    Learn More

    photo of Jeff Zoldy

    Jeff Zoldy

    Jeff is a writer, editor, and marketer based in Charlotte, North Carolina. He has been editing on the Home Solutions team for over a year and is passionate about getting homeowners the information they need when they need it most. When he’s not working, Jeff can be found at baseball games, golfing, going to the gym, reading, watching movies, and playing video games.

    Learn More

    Find a Local Plumber in Your City