Sump Pumps
Updated February 20, 2026
Installed in a sump pit to remove water that collects in basements and crawl spaces. Essential for flood prevention in homes with below-grade living areas.
Overview
Sump pumps sit in a pit (sump basin) below the basement or crawl space floor and remove water that collects from groundwater, rain, or drainage systems. When water rises in the pit, a float switch activates the pump, which pushes water through a discharge pipe to the outside. Submersible pumps sit inside the pit underwater. Pedestal pumps mount above the pit with the motor on top. Submersible is quieter and more common. Every home with a basement in a wet climate should have one -- and a battery backup for when the power goes out during storms.
Pros & Cons
- Flood prevention
- Protects foundation
- Automatic operation
- Battery backup available
- Requires sump pit
- Needs regular testing
- Power failure risk
Key Features
- Automatic float switch activation -- pumps when water rises, stops when it drops
- Submersible design runs underwater in the pit (quieter, more common)
- Pedestal design keeps the motor above water (easier to service, louder)
- Discharge pipe routes water outside and away from the foundation
- Battery backup systems available for power outage protection
Sizing & Selection
1/3 HP handles most residential applications with moderate groundwater. 1/2 HP for homes with frequent heavy water intrusion or long discharge runs. 1 HP for severe water tables or commercial applications. GPH (gallons per hour) at your specific head pressure (vertical lift) is the true performance metric -- not just HP.
Installation
The sump pit is typically installed during construction. Retrofit pits require cutting through the basement floor. The pump sits in the pit, discharge pipe runs up and out through the foundation wall or rim joist, and drains to a point at least 10 feet from the foundation. Check valve on the discharge prevents backflow. The pump plugs into a GFCI outlet near the pit.
Maintenance
- Test every 3-4 months by pouring water into the pit until the pump activates.
- Clean the pit annually -- remove gravel, debris, and sediment that can clog the pump intake.
- Check the discharge pipe exit outside for blockages, ice, or animal nests.
- Replace the pump proactively every 7-10 years. Do not wait for failure during a storm.
- Test the battery backup system monthly if you have one.
Buying Tips
- Zoeller, Wayne, and Liberty Pumps are the top residential brands. Cast iron housing is quieter and lasts longer than thermoplastic.
- A battery backup sump pump (-300) is the single most important add-on. Primary pump failure during a power outage is the number one cause of basement floods.
- Combination primary + backup systems (-600) are the best value for complete protection.
- A sump pump alarm (-25) alerts you when water rises above the normal pump activation level. Cheap insurance.
- If your home does not have a sump pit and you have moisture issues, a waterproofing contractor can install one.