Troubleshooting a Dishwasher That Won't Drain

A dishwasher with the lower rack pulled out.
  • 2 hours
  • Intermediate
What You'll Need
Wrench (to loosen drain pipe)
What You'll Need
Wrench (to loosen drain pipe)

If you find yourself troubleshooting a dishwasher that won't drain, you aren't alone. Although there can be a number of reasons for a dishwasher's failure to drain, it shouldn't present a major challenge for you to find and fix the problem. There are actually a limited number of reasons your dishwasher may not be draining. Follow the troubleshooting steps below to get your dishwasher working again.

Step 1 - Check for Clogs

First, check the sump (bottom) area of your dishwasher. If you have more than one or two cups of water there, use a container and remove as much of it as you can. Then, check to see if there is food debris, papers, or other scraps that might be clogging the drain. If upon first checking, you find only a small amount of water, this is not necessarily a sign that your dishwasher is not draining. Typically, there is a small amount of water intentionally left there to keep the seal from drying out.

Step 2 - Check the Door Latch

An unlatched door will keep your dishwasher from draining. Make sure the door is latched and check your dishwasher again to see if it drains. If you’re having problems with the latch securing the door, you may need to replace it.

Step 3 - Check the Operating Components

If there is a component failure you should be able to spot it by checking the drain valve, pump, motor, solenoid assembly, drain valve, belt, drain line, and air gap. If your dishwasher has a belt-drive, check to see if the belt has broken or has slipped off the pulley. If you need help in identifying any of these components, check your dishwasher owner’s manual or call the manufacturer.

Step 4 - Check Your Garbage Disposal Drain Plug

The drain plug in your garbage disposal (a small plastic insert) should be removed. For a dishwasher draining through your garbage disposal, try running your disposal to be sure this drain is not plugged.

Step 5 - Check for Possible Blocking of the Drain Hose

Locate the drain hose between the pump and drain line and check for a possible blockage or kink. You may have to remove the drain hose to make this check. The hose is held to the drain valve and the disposal by clamps. Loosen these clamps, remove the hose, and inspect it for a blockage. If there is a problem and you are unable to remove it, you may need to replace the hose.

Step 6 - Check the Motor

Test the motor to see if it is running properly. Be sure the dishwasher is plugged into an electrical receptacle and is getting power, then turn on the dishwasher and listen for a hum. If you hear a hum, this suggests the motor is receiving power but is not turning. In this case, you will need to replace the motor.

Step 7 - Check the Drain Valve

Normally, as this valve gets power during the drain cycle, it opens a solenoid and allows water to drain. But not all dishwashers use this valve. If yours does, and it is not working, you may need to replace it.