What North Shore homeowners should check before the next big rain
Sump pumps fail during storms for one main reason: the storm that fills your pit is the same storm that knocks out your power. Lightning, downed limbs, and overloaded circuits take the grid down right when water is coming in fastest, and a standard sump pump without power is just a piece of plastic in a hole.
The rest of the failures are mechanical. A stuck float, a clogged discharge line, an old motor, or a pump that was never big enough for the house. All of them show up at the worst possible time, because heavy rain is the only time the pump really gets tested.
A battery backup pump covers the power problem and gives you a second pump if the first one quits. For a finished basement on the North Shore, it’s the single best thing you can buy for the money.
How does a basement sump pump actually work?
A sump pump sits in a pit at the lowest point of your basement floor. Your foundation’s drain tile collects groundwater from around the footing and sends it to that pit. As the water rises, a float lifts and switches on the pump. The pump pushes the water up a discharge pipe and out of the house, away from the foundation.
In a normal rain the pump runs for a few seconds every so often. In a hard storm, once the ground around your house is saturated, water pushes against the foundation and pours into the pit fast enough that the pump may run almost constantly. If it can’t start, or can’t keep up, the pit overflows onto the floor.
Most basements will see water at some point. Older homes here sit deep in clay soil with a high water table, so the pump isn’t a backup system. It’s the only thing between the groundwater and your floor.
What happens when the power goes out during a storm?
Nothing. That’s the problem. The pit fills, the float rises, and the pump sits there because it has no electricity. In a heavy storm a pit can overflow within minutes of the pump stopping.
The cost adds up fast. Water damage is one of the most common homeowners insurance claims, and a flooded finished basement routinely runs into the thousands once you count carpet, drywall, furniture, and anything stored on the floor. Most standard homeowners policies do not cover sump pump failure or water backup unless you’ve added a water backup endorsement, and many people find that out after the fact.
What are the top reasons sump pumps fail?
Four things cause most of the failures we see:
- Power outage. The primary pump has no electricity during the heaviest rain.
- Stuck float switch. The float catches on the side of the pit or the discharge pipe, or the switch wears out from cycling thousands of times. The pump never gets the signal to turn on.
- Clogged or frozen discharge line, or an undersized pump. Water comes in faster than the pump can move it out.
- Old age. Motors and impellers wear out. A pump that’s seven to ten years old and cycles often is living on borrowed time.
You can catch most of this yourself. A few times a year, and always before storm season:
- Pour a bucket of water into the pit and watch the float rise and the pump kick on and shut off.
- Make sure the float moves freely and isn’t touching the pit wall or the pipes.
- Go outside and confirm the discharge pipe is clear and draining well away from the house.
- Listen for the check valve. If water rushes back into the pit after the pump stops, the valve is bad.
- Scoop any gravel or debris out of the bottom of the pit.
How a battery backup sump pump works
A battery backup is a second pump that sits in the same pit, mounted a little higher than the primary, with its own float and its own power. When the primary pump stops, whether because the power is out or the pump itself failed, the water rises a few more inches, the backup float lifts, and the backup pump takes over. It runs off a deep-cycle battery that stays on a charger the rest of the time.
Equipment and installation typically run several hundred dollars, which is a fraction of one flooded basement.
Installing one right means sizing the pump to your pit and your water, setting the float heights so the two pumps don’t fight each other, checking the discharge line and check valve, and testing the battery under load. We also look at the primary pump while we’re there. There’s no point putting a new backup behind a primary that’s on its last legs.
Frequently asked questions
How long does a sump pump battery backup last during a power outage?
It depends on how hard the pump is working. A good battery will run the pump continuously for roughly 5 to 7 hours, or on and off for a day or two in a lighter rain. If you get multi-day outages, a second battery extends that.
How often should a sump pump be replaced?
Every 7 to 10 years for a typical primary pump. If your pump runs a lot, replace it on the early side rather than waiting for it to die.
Will my homeowners insurance cover basement flooding from a failed sump pump?
Usually not on a standard policy. Sump pump failure and water backup are typically excluded unless you’ve added a water backup endorsement. Call your agent and ask. It’s usually inexpensive to add.
Can I test my sump pump and battery backup myself?
Yes. Pour water into the pit until the float rises and the pump starts. To test the backup, unplug the primary pump and pour again; the backup should kick on. Plug the primary back in when you’re done. What you can’t easily check yourself is the check valve, the battery’s real capacity under load, and whether the pump is sized right, which is what we look at on a service call.
Sump pump and battery backup service on the North Shore
Biagi Plumbing has been installing and servicing sump pumps and battery backup systems on the North Shore since 1989. We work in Evanston, Wilmette, Winnetka, Glencoe, Highland Park, Lake Forest, Lake Bluff, Deerfield, Northbrook, Glenview, Libertyville, Buffalo Grove, and the surrounding communities.
Don’t wait for a storm to find out whether your pump works. Call Biagi Plumbing at (847) 512-8921 to schedule a sump pump check and battery test. We’ll test the primary and the backup, check the float, the check valve, and the discharge line, and tell you plainly whether you’re ready for the next big rain.