How to Deep Clean a Dishwasher

Make sure the dishwasher is completely empty — no dishes, utensils, or dishwasher pods in the dispenser. Pull out both the upper and lower racks and set them on a towel on the counter or in the sink. If the racks have built-up grime or hard-water scale, fill the sink or bathtub with warm water and 1 cup of white vinegar and let them soak for 30 minutes while you clean the interior. Lay a bath towel on the floor in front of the dishwasher to catch any drips.

The filter is the round, cylindrical screen at the bottom of the dishwasher tub — usually near the base of the lower spray arm. Twist it counterclockwise (most models) and lift it out. You may find a coarse mesh filter underneath it as well — remove that too. Rinse both pieces under warm running water, using an old toothbrush and a few drops of dish soap to scrub away the built-up food particles, grease, and slime. Hold it up to the light — every hole in the mesh should be clear. This single step fixes the majority of dishwasher odor problems.

Remove the spray arms — the lower arm usually lifts off or unscrews from the center post, and the upper arm clips or screws off from the underside of the upper rack bracket. Inspect the small spray holes along each arm. Food particles and mineral deposits frequently clog these holes, reducing water pressure and leaving dishes dirty. Use a toothpick or bamboo skewer to poke through each hole and dislodge any debris. Rinse the arms under running water and shake out any loose particles. Snap or screw them back into place.

The rubber gasket around the door is a hidden breeding ground for mold and mildew because it stays damp between cycles. Dip a toothbrush in warm soapy water and scrub along the entire gasket — pull it back gently to clean the fold underneath where black mold often hides. Also scrub the bottom edge of the door and the area around the door hinge where food debris collects but never gets reached by the spray arms during a cycle. Wipe everything down with a damp microfiber cloth.

With the filter removed, look down into the drain well at the bottom of the dishwasher tub. You'll often find broken glass, food scraps, label fragments, or even small utensils that slipped through the rack. Remove any visible debris by hand. Wipe around the drain opening and the surrounding area with a damp cloth. If there's visible mineral buildup or slime, scrub it with the toothbrush and a splash of vinegar. Reinstall the clean filter by dropping it in and twisting clockwise until it locks.

Place the racks back in the dishwasher. Pour 2 cups of white distilled vinegar into a dishwasher-safe glass measuring cup or bowl and set it upright on the top rack. Do not add any detergent. Close the door and run a full cycle on the hottest water setting available. The vinegar dissolves mineral deposits (hard-water scale), cuts through grease, and sanitizes the interior. The steam from the hot cycle carries the vinegar into every spray arm hole, hose, and crevice you can't reach by hand.

After the vinegar cycle finishes, open the door and sprinkle 1 cup of baking soda evenly across the bottom of the dishwasher tub. Close the door and run a short hot-water cycle (or a rinse cycle if your machine has one). The baking soda absorbs any remaining odors, provides a mild abrasive scrub to the interior surfaces, and leaves the tub smelling fresh. When this cycle finishes, open the door and let the dishwasher air-dry for 30 minutes — this helps prevent mold and mildew from forming on the gasket.