A hand on the slightly opened door of a dishwasher

The dishwasher is your go-to cleaning machine—especially after a big meal, when the countertop is piled high with dirty plates, cookware, serving platters, and the like. So you should return the favor by giving your dishwasher a thorough cleaning once in awhile. This will keep the appliance running smoothly, smelling clean, and looking its best.

The following expert tips will help you do the job right. For more on dishwashers, including how we test them, check out our dishwasher ratings and buying guide.

Step 1: Clean the Exterior

If your dishwasher front is made of plastic, use a sponge and hot, soapy water to wipe it down. For stainless steel dishwashers, glass cleaner is effective at removing built-up grime, smudges, and fingerprints. Avoid spraying the cleaner directly onto the dishwasher front, because the moisture could damage its electronic controls.

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Instead, spray the cleaner onto a paper towel or soft cloth, then apply the cloth to the dishwasher. Never use bleach-based wipes, harsh chemicals, scouring pads, and anything abrasive on a stainless door and tub.

Use a rag to clean the seal between the dishwasher door and the tub, where residue and food particles collect. Buildup can cause odors, lead to mold growth, and potentially keep the door from sealing properly.

Step 2: Clear the Filter

This step is vital for manual-clean filters, which are common on newer machines. These filters eliminate the grinder on self-cleaning dishwashers that pulverize food scraps and send them down the drain. The result is much quieter operation, but it also means more scraps get trapped in the filter, which can lead to funky smells.

Once a week or so, pull out the bottom rack and remove the filter system, which usually consists of several interlocking parts. There’s often a center cylinder that unscrews, allowing you to lift out the system and take it apart. Clean the parts individually at the sink, using the spray on your faucet or a sponge; our testers also keep a small brush handy to dislodge coffee grounds and other grainy soil that can clog the mesh filter material.

This is also a good time to check the spray arm for trapped food scraps. It usually lifts off its base with a gentle tug. Rinse the arm under the faucet, inspecting for clogged holes, which can be cleared with a toothpick or wooden skewer. Some spray arms have an additional hole on their underside that’s meant to shoot water into the filter, keeping it clean. Check it for clogs before reinstalling the spray arm and filter system. 

Step 3: Sanitize and Deodorize

Over time, discolorations and odors can build up throughout a dishwasher’s interior. Use a citric-acid-based dishwasher cleaner, such as Affresh or Finish, to remove the deposits monthly.

If the discoloration persists, because of severe mineral deposits from your home’s hard water, you’ll need to switch to a tougher store-bought dishwasher cleaner. We tested three dishwasher detergent additives: Finish Power Up Booster Agent, Glisten Dishwasher Cleaner & Hard Water Spot Remover, and Lemi Shine Original. They all performed well, with Lemi Shine offering the best overall value.   

If you live in an area with very hard water, you may want to consider adding regeneration salt in the dishwasher's water-softening system. This will improve cleaning and help prevent spotting, and the salt helps prevent mineral buildup in the dishwasher.