Dishwashers are supposed to clean dishes, however they don't work very well if the dishwasher itself is not clean.
How often you should clean your dishwasher depends on how much you use your dishwasher, how much food debris you put inside your dishwasher, and the hardness of your water, however most dishwashers should be cleaned about once a year.
Here are the steps for cleaning a dishwasher.
Store Bought Cleaner
There are store bought cleaners made specifically for cleaning a dishwasher. These products usually say to use them monthly to keep your dishwasher clean.
Store bought dishwasher cleaners typically require putting the cleaner in an empty dishwasher and running the dishwasher on the hottest setting.
The prices range from $1 to $5 per cleaning.
These cleaners do a good (but typically not great) job at cleaning dishwashers.
To deep clean your dishwasher, start by removing the bottom rack. Remove any debris in the bottom of your dishwasher and replace the bottom rack.
Fill a dishwasher safe bowl or cup with 1 cup of vinegar and put it in the top rack of your dishwasher. Run hot water in your kitchen sink until it gets really hot to ensure water going to your dishwasher starts hot instead of cold. Run your dishwasher on a hot water cycle.
Sprinkle 1 cup of baking soda over the bottom of your dishwasher and run another hot water cycle, but once again start by running hot water in your kitchen sink until it gets really hot.
After the baking soda wash is complete, remove the bottom rack again and scrub any dirty parts with a toothbrush. If needed, you can remove parts of the dishwasher and hand wash them in your sink with vinegar and water.
Wipe down the dishwasher door inside and outside with warm soapy water. Pay close attention to all of the grooves and crevices. Make sure to dry the door thoroughly to avoid water spots.