The part(s) or condition(s) listed below for the symptom Dishwasher not draining are ordered from most likely to least likely to occur. Check or test each item, starting with the items at the top of the page.
The drain pump uses an impeller to force water through the drain hose. If the drain pump motor is not working, the dishwasher won’t drain. To determine if the drain pump is defective, check the pump motor for continuity using a multimeter. If the motor does not have continuity, or if is getting power but won’t run, replace the drain pump. Drain pumps are not repairable—if the drain pump is defective, you must replace it.
Over time, the drain valve can get clogged with debris. To ensure that water can flow through the drain valve, clean out the valve. If the drain valve is clear of debris but it still won’t actuate, replace it. Drain valves are not repairable—if the drain valve is defective, you must replace it.
If the garbage disposer was installed recently, the drain plug may not have been removed. All garbage disposers are sold with a solid plug in the drain tube. If the dishwasher is not connected to the garbage disposer, the plug must remain in the drain tube. However, if the dishwasher is connected to the garbage disposer, the plug must be removed. If the garbage disposer wasn't replaced recently, it is possible that the disposer is clogged. Remove the dishwasher drain hose from the disposer and clean out both the fitting on the disposer and the end of the drain hose. These are the most common places to find an obstruction if the dishwasher won't drain.
The drain hose might be clogged. To unclog the drain hose, remove the drain hose from both the dishwasher and the sink drain and clean it out. The drain hose is most commonly clogged near the garbage disposer or dishwasher drain branch tailpiece.
The check ball is a small plastic ball in the check valve that prevents water from returning to the dishwasher after the dishwasher has drained. If the check ball gets stuck, it will prevent water from draining through the check valve. If the check ball is stuck, try to free it.