How often should I clean my dishwasher filter?

KitchenAid ties the interval to how many loads you run and whether you rinse or scrape the dishes first:

• 1 to 3 loads a week: once a year if you rinse and scrape, twice a year if you only scrape, every other month if you do neither.
• 4 to 7 loads a week: once a year if you rinse and scrape, twice a year if you only scrape, monthly if you do neither.
• 8 to 12 loads a week: twice a year if you rinse and scrape, every three months if you only scrape, every two weeks if you do neither.

Bosch keeps it general: “For optimum results, we recommend you clean your filter every few months.” Whirlpool's owner's manual for its plastic-tub dishwashers adds the hard-water rule: “If you have hard water (above 15 grains), clean your filter at least once per month.”

You don't have to pre-wash to protect the filter. KitchenAid notes that, depending on the model, you usually don't need to pre-wash dishes, and recommends scraping large pieces of food off plates before they go in.

In KitchenAid's words, the filter “is responsible for clearing dishwater, preventing clogs and keeping food particles off of your dishes”. Bosch's reason is the drain: cleaning the filter periodically helps the dishwasher drain properly.

1. 1

   Take out the bottom rack

   The filter is in the bottom of the tub.

2. 2

   Lift the filter out

   On Whirlpool's plastic-tub models you turn the upper filter a quarter turn counterclockwise and lift it out; on Bosch models you turn the filter knob to the left and lift. Your owner's manual shows yours.

3. 3

   Rinse and brush it

   Warm running water or warm soapy water, and a soft brush for stuck-on bits. Not a wire brush or a scouring pad: Whirlpool's manual rules them out, and KitchenAid warns that a wire brush or wire sponge may damage the filter.

4. 4

   Put it back securely

   Seat it the way it came out before you run the dishwasher again.

Not every dishwasher has a filter you clean by hand. KitchenAid says select models with its Advanced Clean Water Wash System have “a maintenance-free filter system that doesn’t require any regular cleaning or maintenance” — you only empty a small cup now and then. Your owner's manual says which kind you have.

HavnOS puts a monthly filter clean on your calendar for each dishwasher on your house's record. If you run fewer loads or rinse first, change the interval on the task and the dates follow. On the Max plan it also finds your dishwasher's owner's manual and pulls the maker's own maintenance out of it.