Why Your Dishwasher Filter Makes a Difference

After deciding whether you want a third rack in your new dishwasher or extra spray arms to clean your extra-dirty dishes, you might not give much thought to the dishwasher filter. In fact, many consumers buy a dishwasher not knowing whether it has a self-cleaning filter or a manual one they need to clean from time to time.

Electrolux told us that customer feedback alerted the company to this common confusion. “Consumers might not be aware of the type of filter system if they haven’t read the user manual,” says Ashish Verma, a dish-care manager for Electrolux.

While you should always read the owner's manual so you know how to load, use, and properly maintain your dishwasher, it’s not surprising that many wind up unread and filed away in a drawer somewhere.

What the Filter Does
As water and dishwasher detergent circulate through the dishwasher and rinse dirty dishes and glasses, bits of food are washed away, landing in the filter at the bottom of the dishwasher interior. The filter prevents food from redepositing debris on clean dishes and clogging the drain. Not cleaning a manual filter will result in a funky-smelling appliance.

Self-cleaning and manual filters are both effective, but they work differently. 

Self-Cleaning Filters

Self-cleaning filters rarely need your attention. To determine whether that's 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. All self-cleaning filters used to have a grinder that pulverized food so that it easily went down the drain, but that setup tended to be noisy.

To solve this problem, 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 more expensive dishwashers, including some KitchenAid and Kenmore models. (Not all pricey dishwashers have a self-cleaning filter. The KitchenAid KDFE454CSS, for instance, is equipped with a manual filter, and at $1,340 it's not a cheap machine. This high-scoring model excelled in our noise tests.)

Better insulation can also dampen the noise a dishwasher makes. That's why some dishwashers with a regular self-cleaning filter have earned a Very Good in our tests for noise.

Manual Filters

Manual filters tend to be quieter. To determine whether you have this type, look under the plastic blades 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 it for unlocking.

To clean the manual filter, turn and remove the it, then rinse it under running water (shown below) until all the food is gone. Don't forget to wipe away any gunk that’s stuck to the plastic component. Food that collects in the filter can cause the dishwasher to develop bad odors and reduce water flow, so dishes don’t get as clean.

Your owner's manual will tell you how frequently you need to clean the filter, as will the manufacturer’s website.

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