Leak and Freeze
Sump pumps, backups and the pit sensor
A sump pump fails when you need it most: in a storm, when the power is out. How to test it, why a battery backup matters, and where the sensor goes.
A sump pump keeps groundwater out of the basement, and it is most likely to be needed in a storm, which is when the power goes out. FEMA says to choose a pump with a battery-operated backup for that reason. NDSU Extension says to test the pump by pouring water into the pit until the float turns it on, and to make sure it turns on and off at least twice. A leak sensor at the rim of the pit tells you when the water rises past where the pump should have caught it.
Test it before the season
- Pour water into the sump until the float lifts and the pump starts.
- Make sure it turns on and off at least twice, and that the water leaves the house through the discharge line.
- If you have a backup pump, test it too. It only runs when the primary fails, so it is the one nobody notices is dead.
- Keep the backup's battery maintained. A backup with a flat battery is no backup.
Put the sensor at the rim
A sensor on the floor of the pit would read wet all the time. Mount it at the rim, so it reads wet only when the water climbs past where the pump should have taken over. That alert means the pump has failed or cannot keep up.
Check the policy too
Water backing up through a drain or a sump is not covered by many homeowners policies unless you add a sewer and drain backup rider. Triple-I says many policies do not cover it; the insurance guide has more.
Sources
- FEMA: Protect your home from flooding, low-cost projects you can do yourself Federal Emergency Management Agency, accessed October 25, 2026
- NDSU Extension: Check your sump pump North Dakota State University Extension, accessed October 25, 2026
- Triple-I: How to protect your home from water damage Insurance Information Institute, accessed October 25, 2026
Drafted with a language model on October 25, 2026 from the sources listed above, each opened that day. Every threshold and count on the page comes from the site's own code, held by a test. The editor samples pages after they publish; nothing here is an inspection of your house or advice from a licensed plumber or insurer.
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