Checking a dishwasher float assembly:

Common dishwasher float assembly Checking a float assembly
Disconnect the power source to your dishwasher before you conduct this or any other check. Unplug the unit from the wall outlet, remove the appropriate fuse from the fuse box, or turn off the appropriate circuit breaker in the electrical panel.

To inspect the float assembly for proper operation, start by opening the dishwasher door and then remove the lower dish rack. If your dishwasher has a stationary cover over the float assembly, it will need to be removed next. It will either snap in place, or be secured with a screw.

Lift the float and let it drop several times. The float should move freely in the guide tube. If there is a restriction, you will need to remove the float to correct it. The float may simply lift out of the guide tube or may have a retainer attached to the end of the stem that keeps it from becoming dislodged. To detach any retainer, you will have to remove the lower access panel first. The access panel is normally held in place with a couple of screws at either end. With the panel removed you will be able to detach any retainer on the stem, and remove the float to inspect the guide tube for any foreign debris that may be causing a restriction. Check the stem of the float to make sure that it is clean and straight. A float that is warped or damaged will need to be replaced. If you have found any debris in the guide tube make sure to clean it thoroughly. Replace the float assembly and retainer. Route any wires or hoses that might impede the movement of the float or float switch away from the assembly. Check the mechanical operation again to verify that it moves freely. Replace the float cover if your model has one. Replace the lower dish rack and restore power to your dishwasher and run it through a cycle to test it. Replace the access panel if the problem was resolved.

If the dishwasher is still overfilling, the problem may be with the float switch or the water inlet valve.