- One of the most common causes of an overflowing dishwasher is excessive soap suds building up inside the machine and spilling out from the edges. Quality dishwasher detergents usually produce no more than a half an inch of suds on the water surface during a normal cycle, which is not enough to cause an overflow problem. However, putting dish soap or hand soap into the appliance can lead to the dishwasher overflowing with masses of suds. Fuel the dishwasher with vinegar and cold water and run it on a normal cycle to quell any problems with suds.
- Some dishwashers overflow due to faults with the appliance doors. This can be caused by a ripped or damaged door gasket or by problems inside the machine itself. Leaks can originate from the rinse aid dispenser or the dishwasher soap cup. Unplug the dishwasher from the wall outlet before examining these components. Test for leaks by separating the outer door from the inner door using a screwdriver. Push the outer door down to identify whether the insulation surrounding it is wet. The rinse aid dispenser and the cup will need to be replaced if the insulation is damp.
- Water valves are situated behind the dishwasher panel usually around the bottom of the appliance. The water valve is a thin, narrow tube that controls the flow of water to the dishwasher. Run the dishwasher with the control panel off and watch the valve to identify if the water is leaking from it. A leaking water valve should be replaced immediately. Open the dishwasher door to identify whether water is entering the machine from the left side if the valve itself is not leaking. Replace the valve if you can see water coming in.
- Pump seals are situated behind the dishwasher control panel. Leaks that emerge from the base area of the dishwasher motor are usually caused by a problem with the pump seal. Pump seals can be replaced without professional assistance, but some experience with mechanical appliance work is usually necessary. Older dishwasher pump seals have several component parts and casings that need to be removed and reinstalled to fix overflow problems. Newer models, however, have pump seals that can be removed from their casing and replaced with new parts.