Sump pump discharge lines are fed outside the home, meaning it's possible they could freeze during the cold winter months. A backed up discharge line means your sump pump won't work properly in the event of water in your basement, which will make the flooding much worse. The IceGuard fits over the top of your discharge line to provide water with a secondary escape route. When the main line is working correctly, water simply flows out as usual. However, when the discharge line is frozen, the IceGuard allows water to escape through slotted openings in the drain pipe.