Over time, dishwashers can get a buildup of loose dirt or bits of food left on dishes. Typically, any food or dirt particles filter through the drain hose without problems, but the drain hose can clog up, making your dishwasher less efficient. Although you cannot use drain cleaner to solve the problem since it can damage the rubber inside of your dishwasher, you might be able to unclog your dishwasher using other methods.
Commercial drain cleaning products can contain toxic chemicals. When you pour a drain cleaner into your dishwasher, residue from the cleaner could remain after unclogging the drain and washing the inside of the appliance. This residue could attach to your dishes during future wash cycles. The drain cleaner residue could be harmful to your health.
The drain cleaner could also damage the drain hose, or other parts of the dishwasher, which could lead to leaks and other mechanical problems. If it is damaged by drain cleaner, you will have to get new parts, especially hoses for the dishwasher.
Alternative Cleaning Solutions
A combination of baking soda and white vinegar can dissolve minor drain clogs in your dishwasher. To use it, you will have to remove your drain hose. First cut the power supply to the dishwasher, then locate the drain connection and unscrew the nuts holding it in place. Then loosen the screws that hold the dishwasher in place, and then move the dishwasher itself. The drain hose is usually at the back towards the bottom of the machine. Once you find it, place a bucket under it to catch any liquid that comes out and then detach the hose.
To use the clearing liquid, pour one cup of baking soda and one cup of white vinegar into the drain hose on your dishwasher. Allow the mixture to work through the clog, which can take half an hour or more. After the mixture works through the clog, run your dishwasher through a normal cycle to remove any residue. Running your dishwasher on empty with a cup of white vinegar once a month can also help to clean the dishwasher, which will reduce the chance of future clogs.
Most clogs originate in the drain hose attached to your dishwasher. You can remove the drain hose and use an auger or "plumbing snake" to clear out the clog. Use caution when using the auger. The auger could cause damage to the hose, or cut or pierce your skin if used incorrectly. Reattach the drain hose following the user manual instructions before running the dishwasher.
Serious clogs can cause your dishwasher to drain improperly, and the dirty water and debris can back up into the inside of the dishwasher itself. Make sure to clear your your garbage disposal regularly as it may connect to some dishwashers and cause buildup.
If you cannot identify the source of the clog, or if your attempts to unclog the dishwasher fail, contact a licensed plumber. The plumber can unclog the drain before any major damage occurs.