In this video, This Old House plumbing and heating expert Richard Trethewey shows how to keep a basement dry—even when the power goes out.
Installing a Backup Sump Pump
- Unplug, disconnect and remove the old sump pump from the sump pit.
- Apply Teflon tape to the threads on a check valve, then tighten the valve onto side of new 110-volt sump pump.
- Wrap Teflon tape around the threads of the battery-powered pump, then tighten the battery-powered pump onto the check valve. Set both pumps into the sump pit.
- Cut 1½-inch-diameter PVC pipe to length to form discharge pipe. Glue together PVC pipe and fittings and connect to existing discharge pipe with stainless steel hose clamps and rubber connector.
- Set deep-cycle 12-volt marine battery into protective plastic box and set onto a nearby shelf.
- Make the low-voltage cable connections between the battery and backup pump.
- Plug into a 110-volt electrical outlet the battery charger and the power cord for the 110-volt primary sump pump.
- Test the operation of the primary pump by reaching into the sump pit and lifting the flow valve until the pump starts. Repeat to test the battery-powered backup pump.