Things You'll Need
Garden hose with high-pressure nozzle
Wet-dry vacuum or hand siphon
Sump pumps perform an invaluable service in homes and basements that are prone to flooding. In fact, a good pump can save a homeowner thousands of dollars in potential flood damage repair. Even the best pump, however, cannot perform its job if the drainage/discharge pipe is blocked. If you discover that your pump's drainage line is plugged, you should attempt to clear it as soon as possible. Fortunately, this is a task most homeowner's can accomplish on their own.
Check the end of the drain pipe. The end of the drain pipe will be located outside of the house/basement. Typically, the pipe will drain onto a downslope that leads away from the house. If the end of the drain/discharge pipe has a screen in place, remove it. Also remove any debris that has accumulated on the screen.
Disconnect the pump from the electrical outlet. If the pump is not connected to an outlet, turn off the appropriate breaker in your home's breaker box.
Remove any water that remains in the sump pit. You may use either a wet-dry vacuum or a hand siphon to suck the water out of the pit. If you don't have access to either, simply use a small container, such as a coffee can, to manually dip the water out of the pit.
Pull the sump pump unit out of the pit. Most pumps will have a handle designed for lifting the pump. If not, grasp the body of the pump and carefully remove it from the pit. Do not, however, pull the pump by its float switch or power cord.
Disconnect the drainage/discharge pipe from the main body of the sump pump. You will need a screwdriver to loosen the clamp that holds the pipe in place. Loosen the clamp just enough so that you're able to pull the pipe off of the pump.
Run a plumber's snake/auger through the drainage pipe. Start at the end of the pipe that connected to the pump and push the auger through the pipe. If the blockage will not budge, use a garden hose with a high-pressure nozzle to spray water down the drainage pipe. If possible, connect the garden hose to a hot water outlet, as hot water will help loosen the blockage.
Continue forcing the auger/snake through the pipe and applying high-pressure water until the pipe has been successfully cleared.
Reconnect the discharge pipe to the pump after the blockage has been removed and tighten the clamp. Replace any screens that you removed and carefully settle the pump back into the pit. Plug the pump back into an electrical outlet or turn on the breaker.