The dishwasher's float switch controls the amount of water that is allowed into the dishwasher. When the water reaches a predefined level in the bottom on the dishwasher, the float switch turns off the inlet valve. A defective float switch will cause the dishwasher to overflow with water.
- Turn off the power using the appropriate method;
- shut off the appropriate breaker at the main electrical panel, or
- remove the fuse from the fuse panel, or
- unplug the dishwasher.
Figure 1 - Location of float switch in dishwasher
- Turn off the water supply valve to the dishwasher (usually located under the sink), or disconnect hoses from the faucet.
- Below the dishwasher door is a panel. The panel is either held in position with screws and is removable or is hinged to allow it to fold downwards. Remove or open the panel. This panel provides access to most of the dishwasher components.
- Identify the float valve on the inside of the dish compartment on the bottom of the dishwasher. Ensure that it moves up and down with ease. If it seems to stick, clean the stem with a household cleaner and a fiberglass or plastic scouring pad. If it appears to be moving freely then you may have a defective float switch.
- The float switch assembly will be accessible through the removable front panel. The method of mounting will vary depending on the manufacturer. In the float switch assembly pictured it is held in with a round plastic nut accessible from the dish compartment. Some manufacturers bolt the units from the bottom and others use a twist method to release the assembly.
- Remove the assembly and using an ohm (resistance) meter or a continuity checker verify if the switch is functioning. If the switch is defective it will need to be replaced, it cannot be repaired.
- Replace the assembly in the same manner as it was removed. Remember to reinstall the wires on the correct terminals.
- Turn the hot water shut off valve on until you hear water flow, check the fittings and ensure they are not leaking.
- Open the hot water shut off valve all the way and again look for leaks.
- Replace the removable panel or raise the hinged panel as the case may be.
- Turn the power back ON to the dishwasher.
Note 1: You may have to disconnect the wires that attach to the float switch in order to remove the assembly from the base of the dishwasher. In most cases the wires will be attached via slip on lugs. Use a pair of needle nose pliers on the lug portion. Remember to identify which wire is connected to which lug.
Note 2: Some manufacturers encase the switch in the assembly to the point where it cannot be independently replaced and it requires the replacement of the complete float switch assembly. Your appliance parts supplier will know your requirement based on the manufacturer and model number.