Sump Pump Installation
Updated February 20, 2026
A sump pump is the last line of defense between your basement and a flooded mess. If you're replacing an existing pump, the job is straightforward -- pull the old one, drop in the new one, reconnect the discharge. If you're installing one for the first time, you've got more work: cutting into the basement floor, setting the basin, and routing the discharge line. Either way, getting this right is worth every minute -- a failed sump pump during a heavy rain is one of the most expensive plumbing disasters we see.
Overview
A sump pump is the last line of defense between your basement and a flooded mess. If you're replacing an existing pump, the job is straightforward -- pull the old one, drop in the new one, reconnect the discharge. If you're installing one for the first time, you've got more work: cutting into the basement floor, setting the basin, and routing the discharge line. Either way, getting this right is worth every minute -- a failed sump pump during a heavy rain is one of the most expensive plumbing disasters we see.
What to Know
Tools & Materials
- Sump pump (submersible recommended)
- Sump basin (18x24 minimum)
- PVC pipe and fittings (1-1/2 inch)
- Check valve
- Gravel (for basin bedding)
- Hacksaw or PVC cutter
- Level
- Drill with hole saw (for discharge through foundation wall)
Step by Step
-
Dig or prep the pit
If replacing, remove the old pump and clean the basin. For new installations, mark the basin location in the lowest corner of the basement. Cut through the concrete floor with a demolition saw and excavate deep enough for the basin plus 4-6 inches of gravel underneath.
-
Set the basin
Place gravel in the bottom of the hole for drainage and leveling. Set the basin in the hole and check for level. The rim should sit flush with or slightly above the floor. Backfill around the basin with gravel, then patch the concrete around the rim.
-
Install the check valve
Thread or glue the check valve onto the pump's discharge port. The check valve prevents water from flowing back into the basin when the pump shuts off. Arrow on the valve should point up (toward the discharge exit). This is a critical component -- without it, the pump runs constantly.
-
Set the pump in the basin
Lower the pump into the basin and position it centered. Connect the discharge pipe to the check valve. Route the pipe up and through the foundation wall using a hole saw. Seal the wall penetration with hydraulic cement.
-
Route the discharge outside
Continue the discharge pipe outside, aiming it away from the foundation. Extend at least 10 feet from the house. Some homeowners connect to a buried drain line or dry well. The discharge end should have a screen to prevent debris from entering.
-
Plug in and test
Plug the pump into a GFCI outlet. Fill the basin with water from a hose until the float switch triggers. The pump should kick on, push the water out, and shut off when the basin empties. Verify the check valve holds -- you shouldn't hear water rushing back down after the pump stops.
Pro Tips
- Install a battery backup sump pump alongside the primary. Power outages and heavy rain tend to happen at the same time -- that's when you need the pump most.
- Test your sump pump every 3-4 months by pouring water into the basin. A pump that sits idle for months can seize.
- Use a GFCI outlet for the pump, but make sure it's on a dedicated circuit. You don't want the pump sharing a circuit that might trip from another appliance.
- Keep a spare float switch on hand. Float switch failure is the most common reason a working pump doesn't turn on.
Mistakes to Avoid
- Forgetting the check valve -- the pump will cycle endlessly as water flows back into the basin each time it shuts off.
- Discharging too close to the foundation, which sends water right back to where it came from.
- Not using a GFCI outlet. A sump basin full of water and an ungrounded pump is a shock hazard.
- Sizing the pump too small for the water volume. Check the GPH rating against your expected water intrusion.
When to Call a Pro
If you need to break through a concrete basement floor for a new pit, or if your discharge needs to connect to a municipal storm drain, call a pro. Also worth hiring out if your water table is extremely high and you need a more complex system with perimeter drain tile feeding into the basin.
Bottom Line
A sump pump installation protects your basement from thousands of dollars in water damage. Get the basin sized right, don't skip the check valve, and add a battery backup. Test it regularly. The $150-$400 DIY cost is one of the best investments you can make in a home with any water intrusion risk.