What a sump pump does, and what failure looks like
A sump pump sits in a pit, the sump, at the lowest point of a basement. Groundwater collected by drain tile around or beneath the foundation flows into the pit. When the water rises to a set level, a float switch turns the pump on, and it pushes the water up through a discharge pipe and out of the house. A check valve on that pipe stops the water from falling back into the pit when the pump shuts off.
When any part of that chain fails, groundwater rises in the pit and then over the rim. Because sump pumps work hardest during heavy rain and snowmelt, failures tend to happen exactly when there is the most water to deal with.
What owners and managers notice
- Water spreading across the floor from one corner of the basement, usually the utility area.
- A pump that runs constantly but never seems to lower the water.
- A pump that hums without pumping, or doesn't run at all when the pit is full.
- A high-water alarm sounding, on systems that have one.
- In a townhouse row or small building with a shared pit, water showing up in more than one unit's lower level.
Why sump pumps fail
- Power loss. Storms that bring heavy rain also bring power cuts. Without a battery or water-powered backup, the pump simply stops.
- A stuck float switch. Floats can hang up on the pit wall, the pump cord or debris, so the pump never turns on.
- A worn-out motor. Pumps have a finite service life, and one that has run hard for years may fail under load.
- A frozen or blocked discharge line. In winter, a discharge line that empties onto the yard can freeze solid. Leaves, soil or a crushed pipe can block it at any time of year.
- A failed check valve. Water falls back into the pit after every cycle, making the pump work far harder until it fails.
- An undersized pump. In a heavy storm on saturated clay soil, a pump that copes most of the year can be overwhelmed.
- Debris in the pit. Silt, gravel and small objects clog the intake.
The first hour
Keep clear of the pit and anything electrical in the wet area. If power is the problem and it can't be restored, water will keep rising until the rain eases or a pump is running again. Move belongings away from the pit and off the floor. Photograph the pit and the spread of water. If the pit serves more than one home, as in some townhouse rows, tell your neighbors and the association or management office. Contact your own insurer, too; what applies depends entirely on your individual policy and the circumstances.
We'll tell you honestly how soon a crew can get there.
Get a Crew Out TodayHow cleanup after a sump failure works
- Getting the water moving out. If the pump is still down, the crew can use a temporary pump to lower the pit and stop the rise while you arrange a plumber to repair or replace your pump.
- Extraction. Standing water is removed from the floor, and carpet and pad are extracted in finished areas.
- Assessing the water. Groundwater from a sump carries soil and whatever it passed through. Surfaces it touched are cleaned, and porous items it soaked may be discarded.
- Removing what won't dry. Carpet pad, soaked insulation and drywall that wicked water are the usual items.
- Drying. Dehumidifiers and air movers run until slab, walls and framing read dry. Basements are cool, which affects equipment choice.
- Contents. Stored belongings near the pit are sorted and dried or cleaned where they can be.
The restoration crew deals with the water damage. Repairing or replacing the sump pump, float, check valve or discharge line is plumbing work. Many owners have both happen in the same day.
What affects time and cost
The depth and spread of water, whether the basement is finished, and how long water sat before the pump was running again all matter. A few inches across bare concrete is a short job. The same water across a carpeted family room with framed walls takes considerably more. Cleaning adds time when groundwater has carried soil across the floor.
Pricing is upfront, before work begins, with no hidden fees.
Get the price before the crew starts.
Call for Upfront PricingPreventing the next failure
- Add a backup. A battery backup pump, or a water-powered backup where household water pressure allows, keeps the pit under control during a power cut.
- Test before storm season. Pour a bucket of water into the pit and watch the float rise and the pump start.
- Protect the discharge line. Make sure it slopes away from the house, isn't crushed, and can't freeze where it exits.
- Fit an alarm. A simple high-water alarm gives warning before the pit overflows.
- Replace an aging pump on your schedule, not in the middle of a storm.
Related services
- Basement water damage
- Seepage and groundwater
- Ejector pump failure
- Storm and heavy rain
- Water extraction
- Areas we cover
Sump pump failures: common questions
How do I tell if the pump or the float has failed?
If the pit is full and the pump is silent, the float may be stuck or the pump may have no power. If it hums without moving water, the motor or impeller may have failed. If it runs constantly while the water keeps rising, suspect a blocked discharge line or a failed check valve. A plumber can confirm which.
Is sump pit water the same as sewage?
No. A sump collects groundwater, not wastewater from toilets and drains. Groundwater still carries soil and whatever it has passed through, so floors and surfaces it touched should be cleaned, and soaked porous items like carpet pad are usually discarded rather than dried.
Why did the pump fail during the storm, of all times?
Because that's when it runs hardest and when power cuts are most likely. A pump that has been wearing out for months may finally fail under a long, heavy run. That's why a backup system is worth considering in basements that rely on a sump.
My discharge line froze. Can I thaw it?
Gently, where it's exposed outside, using warm water or a hair dryer on the pipe, never an open flame. If you can't reach the frozen section, a plumber can help. Until it's clear, the pump can't move water out even though it's running.
Do all homes in Northern Virginia have a sump pump?
No. They're common in basements with interior drainage or a high water table, and less common in homes on well-drained ground. Many townhouses and newer single-family homes have them. If you have a pit in the basement floor with a pump in it, that's your sump.
How long does cleanup take after a sump failure?
Extraction is usually the same day. Drying often takes several days, longer in a finished basement or if the concrete was wet for a long time. Once the moisture is mapped, the crew prices the job.
We share a sump with the townhouse next door. Who should be told?
Both households and the association or management office. Shared systems affect everyone connected to them, and the association may need to arrange the pump repair. The crew can work in each affected unit once access is arranged.
What's the difference between a sump pump and an ejector pump?
A sump pump moves groundwater out of a pit in the basement floor. An ejector pump lifts wastewater from a below-grade toilet, shower or laundry up to the main sewer line. Ejector failures involve wastewater and are handled differently.