Keeping the Sump Pump Running in an Outage

The cruel thing about Midwest storms: the same thunderstorm or snowmelt that fills your sump pit also knocks out the power. A sump pump without power is just a hole in the floor filling with water. In a wet spell, a basement can flood in hours, ruining furnaces, water heaters, freezers and everything stored down there.

Here are your options to keep it running.

011. Battery backup sump pump

A second pump installed in the pit, slightly higher than the main one, powered by a deep-cycle battery and charger. When the power goes out or the main pump fails, it kicks in.

• Pros: automatic, works when you're not home, also covers a failed main pump.
• Cons: run time is limited by the battery, from hours to a day or two depending on how hard it's working. Batteries need replacing every few years.
• Tip: buy a system with an alarm, and test it twice a year.

022. Water-powered backup pump

Uses your city water pressure to suck water out of the pit. No electricity needed.

• Pros: runs as long as city water pressure holds; no battery.
• Cons: uses a lot of water; needs good municipal water pressure; won't work on most well systems (no power, no pressure). Many need a plumber and may require a backflow preventer by code.

033. Generator

A portable generator can run the main sump pump through an extension cord (if it plugs in) or a transfer switch or interlock (if it's hard-wired).

• Pros: can run for days with fuel; also runs the fridge and furnace.
• Cons: someone has to be home to start it and refuel it; sump pumps have a big starting surge. See how to size a backup generator and generator safety.

044. Portable power station

A large power station can run a sump pump for a limited time if it can handle the starting surge. Check the specs carefully; many small units can't start a pump.

05The best plan: layers

Many basement owners in wet areas use two layers: a battery backup for automatic protection when they're asleep or away, and a generator for long outages.

06Maintenance that prevents most failures

• Test the pump each spring and fall: pour a bucket of water in and watch it cycle.
• Clean the pit and check the float switch moves freely.
• Check the discharge line outside isn't clogged or frozen.
• Replace an old pump before it fails; many last around 7–10 years.

A sump pump failure is one of the most expensive outage problems a Midwest home can have, and one of the cheapest to prevent. Our fall home checklist has it on the list for a reason.

Photo: 2023-07-30 20 08 18 A newly-installed sump pump in the basement of a house along by Famartin, CC BY-SA 4.0.

Related: Midwest Power Outages: How Long They Really Last (NIPSCO's August Storm)