How to Adjust a Tethered Float Switch Level on a Sump Pump

Design and Function

• Sump pumps are designed to pump collected water from an area of lower elevation to an area of higher elevation. They are often found in areas near homes or other structures where water collects, such as near downspouts and rooflines. The water level rises as it collects in the storage tank. A float switch rests on the water's surface and rises along with the water. When the float switch and the water level reach a preset point, the pump is triggered and begins to push water from the storage tank into a conveyance pipe that channels the water into a drainage system.

Adjustments

• The floating portion of the switch, also called the balloon, is adjusted by the tether. The tether is a piece of tubing or string that attaches the balloon to the switch that turns the pump on or off. The tether's length determines how far it will float from the pump to the upper portions of the water storage tank. Shorten the tether to decrease the water level that triggers the pump and lengthen the tether to increase the amount of water it takes to trigger the pump.

Placement

• The tethered float switch can be attached to the conveyance pipe that runs from the pump to the top of the storage tank. A clamp holds the tether to the pipe; once water reaches the appropriate level, the float levels out and triggers the pump. Other types of sump pumps are designed with the tether attached to an electrical line that feeds power to the pump. Always follow specific manufacturer's instructions regarding tethered float switch placement. Most tether adjustments are made by adjusting the length of the tether and the clamp's tightness.

Considerations

• The float switch must float free from the sides of the storage tank and any electrical lines and portions of the pump mechanism. Avoid tangled tethers and float switch failures by ensuring that the float has clearance from these obstacles. The float switch should have a minimum 2-inch clearance from the top of the water storage tank.