Over time, dishwashers stop cleaning as well as they used to and need to be cleaned. The Kitchn points to two parts of your dishwasher, the trap and the seals, that might be in need of care.
Picture: Tom Page/Flickr
It might sound counterintuitive to clean a machine that's made for cleaning, but your dishwasher catches all kinds of gunk throughout the day. To keep it running smoothly, just keep clean two parts of it:
Clean the dishwasher trap: Down in no mans land, under the lower sprayer, there's usually a piece that is removable. Under it you'll usually find bits of food that didn't make it out the drain or even pet hair (eww) if you have a fur-ball of any kind running around your home. Sometimes the tray comes out fully so it can be rinsed in the sink; sometimes a towel is needed to remove the gunk build-up.
Clean the dishwasher seals: After a few months of use, your dishwasher accumulates a little bit of ick and stick around the rubber gasket in the door as well and often around the soap door as well. Make sure to give them a once-over with a damp towel to keep the grime down.
As for normal cleaning, the Kitchn recommends running your dishwasher with a cup of white vinegar now and again to clean out old food particles and keep it fresh. Combine all that with a properly loaded dishwasher, and you'll have clean dishes every time.
10 Tips to Help the Dishwasher Run Better [The Kitchn]