A dishwasher’s float monitors the water level inside the machine. The float rises with the water level, sending feedback to the dishwasher’s pump to stop the flow of water into the dishwasher. The water level may rise inside the dishwasher if the drain becomes clogged with food particles washed off the dishes. If the drain clogs and water starts to rise inside the tub, the float prevents the water from reaching the point where it flows around the door and spills out, possibly damaging the kitchen floor and the room below the kitchen.
The float sits in the bottom of the dishwasher’s tub. Whether the float sits toward the front, back or middle of the dishwasher’s tub depends on the model dishwasher. The float may sit under a domed cover or it may be exposed. You must roll the bottom cage out of the dishwasher to access the float.
Once you can access the float, remove the cover if one is installed. The cover may be secured by a screw or a metal arm, or it may just snap into place over the float, requiring you to twist it and pull up to remove it. Once you remove the cover, on most dishwashers you can carefully pull up on the float to remove it from its mount. Scrub all food debris on the float, cover, mount and any other parts associated with the float, using an old toothbrush. Once you have loosened the debris, wipe it off the float with a rag or paper towel.
With the float and its various parts clean, you can reassemble the float and test it to ensure the dishwasher fills with water but does not flood. Before you put the float’s cover back in place, insert the float onto its mount, then raise and drop it several times to check its movement. If the float slides up and down without hesitation, then the float should operate correctly. If you still find that float sticks, look for and remove any obstructions impeding its movement.