If the glasses, plates and bowls you pull from the dishwasher rack post-cycle look barely any better than when you stuck them in, it could be a small part of your dishwasher that's causing the problem.

Your dishwasher's filter quietly does some heavy lifting, trapping loose food particles to keep them out of that circulating wash water. If it's clean and installed properly, it means less need to pre-rinse dishes and a better chance that they come out sparkling. But if it's covered in food particles, that's where the problems could arise. 

When compiling and analyzing our list of the best dishwashers, every expert I spoke with said that one of the most common causes for dishwasher repair calls and warranty claims is failing to clean the filter. 

So, how often should you clean your dishwasher filter? It's more important than most people realize. Let's explore why your filter matters, how often you should clean it and the best way to do so.

Your dishwasher filter matters. Here's why

An effective dishwasher filter has three benefits: It keeps the water cleaner, protects the water pump and prevents food debris from clogging spray nozzles and drainage lines. As a result, the dishwasher requires less effort to run, and you'll eliminate wildcards that can damage your expensive kitchen appliance.

In contrast, my ancient Maytag PDC3600AWX portable dishwasher lacks any sort of filter. This means I need to be very diligent about scraping and pre-cleaning when loading to keep it running smoothly.

How to clean your dishwasher filter

Even if you regularly run a self-clean cycle on your dishwasher with a product like Affresh, solid food debris won't disappear unless you empty the filter. Here's a quick guide to cleaning your dishwasher filter.

1. Pull out the lower rack to access the filter assembly at the bottom of your dishwasher. You may also need to move the wash arm slightly to access the filter.
2. Rotate the filter to unlock it before removing it. Keep in mind that your filter might have two parts: an inner cylindrical filter and a flat outer screen. You should clean both of these.
3. Rinse the filter with clean water in your kitchen sink. If food debris and hard water remain, you may need to scrub with a soft brush (abrasive scrubbing can damage the filter mesh) and soapy water.
4. Some brands suggest drying the filter assembly before putting it back in your dishwasher. However, you should be fine reinstalling it before it's dry, as the lingering moisture is unlikely to cause issues for a product that constantly deals with water and dishwashing chemicals.
5. Don't forget to turn the filter to lock everything back in place.

How often should you clean your dishwasher filter?

In the absence of unified manufacturer guidance, I recommend checking your dishwasher filter at least once a month. If it's clean, your job is already done. If not, then it's time to clean it.

Best of all, it's as easy as putting a reminder on your phone, calendar or chore wheel to check and clean the dishwasher filter. However, you should also stay on top of any decline in performance or foul odors in your dishwasher, which might mean it's time to clean the filter ahead of schedule.

You can also simplify the scheduling (and cleaning) process by always scraping food scraps into the trash. This one habit easily turns filter cleaning into a monthly task at most -- even with two daily wash cycles -- rather than something to dread twice a week without any scraping.

For context, some brands provide detailed filter cleaning schedules based on how often you run your dishwasher and how much you pre-clean (scraping and rinsing) dishes before loading. Scraping is easily the deciding factor in preventing frequent filter clogs.

Normally, I'd defer to manufacturers on how often to clean your dishwasher filter, but the advice in the user manuals for our best dishwasher picks is inconsistent. For example, Bosch (PDF) and LG recommend checking and cleaning filters after every dishwashing cycle. In contrast, brands like Samsung (PDF), Midea (PDF), KitchenAid (PDF) and Frigidaire (PDF) give vague instructions about cleaning periodically or as needed.

Even companies like Whirlpool (PDF) and Maytag (PDF), which recommend cleaning your dishwasher filter every one to three months, muddy the waters by stating that the frequency depends on your usage. I mean, technically, they're not wrong. Someone like me, who uses a dishwasher once a week, may not need to clean the filter more than once every few months, compared to busy households that run multiple loads daily.

Even with a relatively dirty dishwasher filter, you're unlikely to need more than 10 minutes to finish the cleaning process. Now you can enjoy a fresher, more effective dishwasher.