The Dishwasher Check Valve Is Leaking in the Sink

Dishwasher Information

• Dishwashers, regardless of the make or the model, operate in a similar fashion. A valve inside the dishwasher opens to allow water into the machine. Once in the machine, the water mixes with soap. The dishwasher pump takes the water and pushes it through the dishwasher spray arm. As the water passes through the sprayer, it causes the arm to rotate and distribute the soapy water over the dishes. The dirty water is pumped out, and the cycle repeats, only this time using clean water. After the clean water is pumped out, a drying element inside the washer dries off the dishes.

Check Valves

• The purpose of a check valve in a dishwasher is to keep water flowing only in one direction. In some washers, the check valve is nothing more than a simple rubber flap. The flap only opens outward, which prevents water from flowing back into the pipes. The purpose of a check valve is to prevent contamination of the municipal water supply if the water in the washing machine backs up and creates a siphoning action.

Working Safely

• When performing any kind of work on the dishwasher, always turn off the electricity for the unit before doing anything else to prevent accidents. it's also a good idea to turn off the water supply valve, usually underneath the nearest sink, to the dishwasher to prevent leaks.

Replacing the Check Valve

• The check valve is usually located beneath the dishwasher spray arm, just after the inlet valve. Access the check valve by removing the lower dish rack and the dishwasher spray arm. Use a wrench to loosen the retaining screen beneath the spray arm. If a large object protector is present, remove this screen as well. Remove the pump housing to gain access to the check valve. Pull the old check valve out of place and insert a new one. Replace the large object and retaining screens. Replace the dishwasher spray arm and secure with the spray arm bolt.

Dishwasher Inlet Valves

• Check the dishwasher inlet valves for proper operation. These are located directly behind where the water supply pipe connects. Access these components by removing the kick panel at the bottom of the dishwasher door with a screwdriver. Disconnect the water supply hose--keep a towel on handy to wipe up any water that dribbles out--and disconnect the wiring harness. Use an ohmmeter to check continuity across the inlet valves, and replace if faulty.

Drain Line Routing

• If the leaking water inside the dishwasher is backing up into the sink, there's a good chance that the drain line isn't routed properly. Make sure that the middle portion of the drain hose is raised higher than both the connection at the dishwasher and the inlet on the garbage disposal or sink tailpiece. Secure the drain hose to the cabinet or wall to keep in place with clamps.