A float pump is an inexpensive way to automate the operation of a sump pit or other tank or pond pump. It can also be a valuable tool in monitoring water level and in identifying problems in your pumping system.
Most float switches have an internal switch (reed or magnet-based) that moves up or down as the liquid levels change. They operate based on whether the wiring is normally open or closed, with the float switching power to the pump when it is in the up position and shutting off the pump when it is in the down position.
The float switches come in a wide variety of shapes, sizes and construction materials to meet your particular application. They are usually easy to install and require no maintenance other than the occasional inspection. They work with most pumps and can be used with multiple pumping systems to control them all from a single controller.
Narrow angle float switches have only a few inches of range where the switch will turn on or off. This means that a small change in the water level could be enough to cause it to turn on or off, even ripples in the surface of the water or splashed from the pump.
The best float switches will have a connector for plugging into a standard power outlet. They should have the correct style of connector for your pump and be compatible with the voltage you are using. Avoid having to splice in cords in wet environments as this can create electrical problems and pose serious safety risks.