The most common reason for sump pump failure is a clogged impeller. The impeller is the rotating part of the pump that actually moves the water. If it becomes clogged with debris, then the pump can't function properly. Other causes of sump pump failure include a worn out motor, a broken switch, or a loose connection.

One of the most common reasons for sump pump failure is when the float switch gets stuck in the up or down position. If the float switch gets stuck in the up position, it can cause the pump to turn on and off continuously, which can overheat and damage the motor. And if the float switch gets stuck in the down position, it can prevent the pump from turning on at all. Other common causes of sump pump failure include clogged impellers, worn out seals and bearings, and a loss of power caused by a tripped circuit breaker or blown fuse.