How Does A Sump Pump Float Switch Work?
A sump pump-float switch turns the sump pump on and off when the water level in the sump pit reaches a specific level.
There are different design variations for various makes and models of pumps. However, with the exception of an electronic switch, which operates by reading variations in water pressure, most sump-pump switches work in an identical fashion to the float switch in your toilet tank, except in reverse.
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How a Sump-Pump Float Switch Works
The float on the sump pump is connected to a switch that turns the pump on and off. The float lays on top of the water and rises and falls as the water level in the sump pit goes up and down.
As the water rises, and the float reaches a certain level, the pump is activated and it expels the water from the pit. As the water falls, and the float drops back down, the pump shuts off until the water rises again.
Causes of Sump-Pump Float Switch Failure
While a sump-pump float switch will usually operate flawlessly for years, sometimes issues do arise.
However, before assuming the switch is the problem, you should confirm there is power to the unit by checking the cord and circuit breakers and/or fuses. If there is power to the pump, there are really only two basic reasons a sump-pump float switch may stop working.
Mechanical Failure
Either from old age or just a bad part, mechanical failures with the switch itself or the float do occur. This is especially true if the pump is over five years old and almost guaranteed if it is more than 10. Be sure to check your warranty to determine the duration of coverage and what parts are covered.
Mechanical failure can also occur if the pump is overworked because it does not have the capacity to pump the volume of water entering your basement. Make certain you have a pump that is properly rated for your situation.
A Stuck Switch
Debris, such as a stick or leaf particles, or rust can accumulate in and/or around the switch itself or on the activation arm that can prevent the switch and/or arm from moving into the “on” position.
While something can become lodged in the switch apparatus at any time, giving the pump a thorough cleaning once every few months is good insurance and will help the pump last a lot longer.
Unplug the pump and remove it from the sump pit. Rinse it off with clean water, gently scrub the pump with an old toothbrush, rinse it off again and reinstall it into the pit.
