As water and dishwasher detergent circulate through a dishwasher and clean dirty dishes and glasses, bits of food are washed away, landing in the filter at the bottom of the dishwasher.

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"The filter prevents food from redepositing debris on clean dishes and clogging the drain," says Larry Ciufo, the engineer who oversees Consumer Reports' dishwasher tests.

Your dishwasher has either a self-cleaning filter or a manual filter. Both filter types are effective, but they work differently.

The biggest difference is that you need to regularly clean a manual filter. Skip this maintenance and the food that collects in a manual filter can cause bad odors and reduce water flow, so dishes won’t get as clean.


Check the Features & Specs tab in our dishwasher ratings to see which kind of filter each model has. Also, if you're in the market for a new machine, see our dishwasher buying guide.
 

Self-Cleaning Filters

Self-cleaning dishwasher filter.
A self-cleaning dishwasher filter.

Self-cleaning filters rarely need your attention. To determine whether this is the type you have, look inside the dishwasher for a plastic grid or series of holes at the base of the machine that cover the filter, like the one above.

Self-cleaning filters used to have a grinder that pulverized food so that it easily went down the drain, but they tended to be noisy.

To address the noise issue, many self-cleaning filters now have an ultrafine mesh filter. The rush of water forces food through the filter, breaking it into tiny particles that wash away.

This type of self-cleaning filter is quieter than one with a grinder and is found on some more expensive dishwashers, including some Kenmore and KitchenAid models.

Better insulation can also dampen the noise a dishwasher makes. That's why some dishwashers with a standard self-cleaning filter have still earned decent scores in our noise tests.

Manual Filters

Manual dishwasher filter.
A manual dishwasher filter.

Manual filters tend to be quieter, but they require occasional maintenance. To find out whether you have this type, look under the plastic spray arms at the bottom of the machine's interior and you'll see a round plastic part, like the one shown above, that resembles the filter on some carafe water filters. Arrows on top might indicate which direction to turn the filter for unlocking and locking when you clean it.

To clean the manual filter, turn and remove it, then rinse it under running water (photo below) until all the food is gone. Wipe away any gunk that’s stuck to the plastic component. 

Check the owner's manual or manufacturer’s website to find out how frequently you need to clean the filter.

Manual dishwasher filter.

Before You Shop for a Dishwasher

You'll find more than a hundred models from more than two dozen brands in our dishwasher ratings. Check out the Features & Specs tab to learn more about each model, including whether it has a manual or self-cleaning filter. See our brand reliability survey results to learn what more than 42,000 readers had to say about their dishwasher brand.

Get the Most From Your Dishwasher