Sump Pump Basics: Do You Need One, How to Test It, and What It Costs

by the Berry team · Updated October 20, 2026

A sump pump sits in a pit at the lowest point of a basement or crawl space and pumps out groundwater before it can flood the house, and you will usually find one in homes with basements in wet areas. If you have one, test it a couple of times a year by pouring water into the pit and making sure it switches on, pumps the pit down, and shuts off.

Common sump pump problems and what they cost to fix

If you have a sump pump, these are the problems you are most likely to run into, ordered roughly from most to least common. Not sure whether you have one? See how to tell if your house has one.

Problem	How to recognize it	DIY cost	Pro cost
Stuck or tangled float switch	The pit fills but the pump never turns on, or it runs and will not shut off. Often the float is caught on the pit wall or a cord.	DIY$0 to free it, $20-$60 for a new switch	Pro$150-$300
Unplugged or tripped outlet	The pump is silent with water in the pit. The plug was bumped, or a GFCI outlet or breaker tripped.	DIY$0	ProUsually not needed
Failed check valve	Water flows back into the pit after the pump shuts off, and the pump cycles on and off more than it should.	DIY$15-$40 for a new valve	Pro$100-$250
Clogged or frozen discharge line	Pump runs and hums but the pit does not go down, or water spills out where the line exits the house.	DIY$0-$50	Pro$150-$400
Worn-out pump	Pump is loud, runs constantly, or cannot keep up with water coming in. More likely if the pump is older.	DIY$100-$400 for a new pump, if you are comfortable swapping it	Pro$300-$1,200 installed
No backup power	Storms that bring heavy rain often also knock out power, which leaves a standard pump unable to run.	DIY$150-$400 for a battery backup unit	Pro$400-$1,200 installed

Ranges are typical US prices and vary with your region, your home, and the season. A pro quote for your exact job beats any range.

What a sump pump does

Some houses sit where groundwater rises after heavy rain or snowmelt. A sump pump collects that water in a pit (the sump) dug below the basement or crawl space floor, often fed by drain tile around the foundation. When the water rises, a float switch turns the pump on, and the pump pushes the water out through a pipe that empties outside, away from the house.

When it works, you never notice it. When it fails during a storm, the basement or crawl space can take on water fast. That is why the most important thing about a sump pump is knowing it works before you need it.

How to tell if your house has a sump pump

Look at the lowest corner of the basement or crawl space. A sump pit is usually a round basin, often 18 to 24 inches across, set into the floor with a lid. You may hear the pump or see a pipe rising out of it.
Follow the pipes outside. Walk the outside of the house and look for a pipe, often white PVC or a black flexible hose, coming out of the foundation wall near ground level and draining into the yard.
Check the inspection report. If you bought the house recently, your home inspection report should mention whether there is a sump pump and its condition.
If you do not find one. Many homes do not need one. Houses on a slab, homes in dry climates, and homes on well-drained lots often never have one. If your basement or crawl space stays dry through heavy rain, that is usually a good sign.

Do you need one?

A sump pump is worth considering if water has come into your basement or crawl space after heavy rain, if the ground around your foundation stays soggy, or if neighbors with similar homes have them. A plumber or waterproofing contractor can tell you whether a pump, better grading, or fixing gutters and downspouts is the right fix. Sometimes the cheaper exterior fix solves the problem.

Installing a new sump pump where none exists is a bigger job than replacing one. It means cutting into the floor, digging the pit, and running a discharge line, and quotes vary widely, often $1,500-$4,000 or more depending on the floor, access, and whether drain tile is added.

How to test a sump pump

If you have one, test it at least twice a year, ideally before spring rains and before winter. It takes about five minutes.

Check that it is plugged in and that the outlet has power. If it is a GFCI outlet, press reset.
Lift the lid and look for debris, a float caught on the side of the pit, or a cord tangled around the float.
Slowly pour a bucket of water into the pit until the float rises.
Watch for three things: the pump turns on, the water level drops quickly, and the pump shuts off on its own.
Go outside and make sure water comes out of the discharge pipe and flows away from the house.

Keeping it working

Clean the pit once a year. Remove gravel, silt, and debris that can jam the float or clog the intake.
Listen to the check valve on the discharge pipe. A loud thunk when the pump shuts off is normal. Water draining back into the pit is not.
If you get hard freezes, make sure the outdoor end of the discharge line is clear and slopes so it drains completely. A frozen line leaves the pump with nowhere to send water.
Point the discharge well away from the foundation, so the water does not just seep back into the pit.
Consider a battery backup if you lose power during storms or if the basement holds anything valuable. See storm and tornado prep for the rest of a storm plan.
Know its age. Many pumps last somewhere around 7 to 10 years, depending on how often they run. If yours is older and runs a lot, replacing it on your schedule beats replacing it during a storm.

When to call a pro

Water is coming into the basement or crawl space and the pump cannot keep up.
The pump runs constantly, or cycles on and off every few seconds, even after you clear the float.
The pump hums but does not move water, and the discharge line is clear.
You want to add a pump, a battery backup, or a second pump and are not comfortable with plumbing and electrical work.
Water has already reached outlets, the furnace, or the water heater. Turn off power to the area if you can do so safely, and get help.

What makes it worse if you wait

A pump that has quietly failed gives no warning until the next heavy rain, which is exactly when you need it.
Even a few inches of water in a basement can ruin flooring, drywall, stored items, and mechanical equipment.
Moisture left behind after a flood can lead to mold within days.
Replacing an old pump during a storm means paying emergency rates, if you can get someone at all.

Common questions

How do I know if my house has a sump pump?

Look for a covered pit in the floor at the lowest point of the house, in a basement or crawl space if you have one, often with a pipe rising out of it. Outside, look for a discharge pipe coming out of the foundation near ground level. Your home inspection report should also mention it.

How often should I test a sump pump?

At least twice a year, ideally before spring rains and before winter. Pour a bucket of water into the pit and make sure the pump turns on, empties the pit, and shuts off on its own.

How long do sump pumps last?

Many last somewhere around 7 to 10 years, but it depends heavily on how often the pump runs and the quality of the unit. A pump in a pit that fills often will wear out sooner.

How much does it cost to replace a sump pump?

A replacement pump typically costs $100-$400 for the unit, or $300-$1,200 installed by a plumber. Adding a sump pump where there was none is a larger job that often runs $1,500-$4,000 or more.

Do I need a battery backup sump pump?

If you lose power during storms, a battery backup is the only way a sump pump keeps running when you most need it. It is most worth it if your basement has flooded before or holds things you cannot afford to lose.

Not sure that's your problem? Snap a photo and Berry will tell you what it is and what it should cost.

Try Berry free Download on the App Store