Two key components of the bilge pump system are the water level sensor and the pump itself. If the pump sensor is a simple float switch, then it will rise with an increase in bilge water. As the float switch rises, it turns on the bilge pump motor. As the bilge water level drops, the float will lower and turn off the bilge pump motor. It’s a very simple operation if working as designed.
Mom always said to keep your room clean, and the engine room is no exception. Be sure that the bilge area is free of old dirt and sludge. Grime in a wet bilge will affect the mobility of a float switch.
If the float has restricted movement, you may have two concerns. First, the float may not rise to turn on the bilge pump. Second, if it does turn on and the water is deep enough, the float switch could get stuck in the on position. In this case, the bilge pump will continue to run…and run…and run until you notice and intervene.
If the bilge pump motor runs dry for too long, it will overheat and seize. A float switch with a built-in safety cover will prevent obstructions from interfering with the float device.