If a sump pump failure occurs, will you find out the hard way? Installed inside a covered basin in the basement floor, sump pumps tend not to get much attention—until they fail, that is. When the basin overflows with infiltrating groundwater that didn't get properly pumped out, or a water pipe ruptures and the pump doesn't actuate to prevent major basement flooding, the situation suddenly becomes obvious.
Here are a few likely causes of sump pump failure:
- Clogged inlet screen. A screen on the inlet located at the bottom of the pump filters out debris that might clog the pump mechanism. If the pump screen and the basin aren't cleaned at least once a year, debris accumulating on the screen may block the intake of water and the pump will fail to function when it's needed.
- Faulty float switch. As the level in the pump basin rises, a float switch actuates the pump to remove water. A stuck or defective switch means the pump doesn't turn on and the basin rapidly overflows, causing basement water damage before it's noticed.
- Burned out motor. While pump motors may fail simply from age, another cause is a defective float switch. In this case, the switch may actuate the pump correctly but fail to turn the pump off. The pump runs continuously and overheats, eventually failing completely. Because it's installed in a basin down in the basement, a continuously running sump pump is often not obvious to residents upstairs.
- Defective backflow valve. As the pump empties the basin and turns off, a backflow valve located in the discharge line prevents water from flowing backward into the basin. If this valve is faulty, backflow into the basin will quickly trigger the pump to actuate again. The pump empties the basin, turns off, then activates again immediately due to backflow entering the basin. This continuous on-off-on operation will cause the pump to fail prematurely.
Annual sump pump maintenance is a good practice to ensure that when the pump's needed most, it will do the job. Sump pump maintenance is typically provided by a qualified local plumber.
