Your dishwasher cleans your dishes, but nothing cleans your dishwasher. Over time, food particles, grease, mineral deposits, and soap scum accumulate inside the tub, filter, and spray arms, leading to cloudy glasses, funky odors, and reduced cleaning performance. Knowing how to clean a dishwasher takes about 30 minutes and should happen once a month to keep the machine running at its best.
Clean the Filter First
Most modern dishwashers have a removable cylindrical filter at the bottom of the tub, usually beneath the lower spray arm. Twist it counterclockwise and lift it out. You may find a secondary flat mesh filter underneath.
Rinse both pieces under warm running water, scrubbing gently with an old toothbrush to remove trapped food debris, grease, and slime. If the filter has a brown or yellow tint, soak it in warm water with a tablespoon of white vinegar for 15 minutes before scrubbing. A clogged filter is the number-one cause of dishes coming out dirty, and cleaning it alone often solves performance problems.
Replace the filter by inserting it and twisting clockwise until it locks. Run your hand over it to confirm it sits flush with the tub floor.
Clear the Spray Arms
Spray arms have small holes that shoot pressurized water across your dishes. Mineral deposits and food particles clog these holes over time, creating uneven water coverage and leaving dishes half-clean. Remove each spray arm by unscrewing the retaining nut or pressing the release tab, depending on your model.
Hold each arm under running water and use a toothpick or straightened paper clip to poke through every hole. You will be surprised how much debris comes out even from a relatively new machine. For heavy mineral buildup, soak the arms in a basin of white vinegar for 30 minutes before clearing the holes.
Reinstall the arms and spin them by hand to confirm they rotate freely without hitting the dish racks.
Wipe Down the Door and Gasket
The door edges, gasket seal, and the area around the hinges never get washed during a normal cycle. Pull back the rubber gasket along the bottom of the door and wipe it with a cloth dampened with a 50/50 mix of white vinegar and warm water. Black mildew spots are common in this area and respond well to a paste of baking soda and water applied with a toothbrush.
Clean the door edges, the top of the tub opening, and the control panel area with the same vinegar solution. Food residue accumulates in the crevice where the door meets the tub, and ignoring it is a primary source of dishwasher odor.
Run a Vinegar Wash Cycle
Place a dishwasher-safe measuring cup or bowl filled with 2 cups of white distilled vinegar upright on the top rack of an otherwise empty dishwasher. Run a normal hot water cycle. The vinegar breaks down grease, dissolves mineral deposits, and eliminates odor-causing bacteria throughout the tub, spray system, and drain lines.
Do not add dish detergent to this cycle. The vinegar works best on its own, and mixing it with detergent reduces its effectiveness. If your dishwasher has a sanitize or heavy cycle option, use it for maximum water temperature.
Follow With a Baking Soda Rinse
After the vinegar cycle completes, sprinkle one cup of baking soda across the bottom of the empty dishwasher tub. Run a short hot water cycle. The baking soda brightens the interior, removes stains from the stainless steel or plastic tub, and neutralizes any lingering odors the vinegar cycle missed.
When this cycle finishes, open the door and let the interior air dry for 30 minutes. The tub should look noticeably cleaner, and any musty smell should be gone.
Clean the Drain and Disposal Connection
Check the drain area at the bottom of the tub for debris. Remove any chunks of food, broken glass, or labels that may have washed off jars. If your dishwasher connects to a garbage disposal, run the disposal before starting the dishwasher to ensure the drain line is clear. A backed-up disposal is a common cause of standing water in the dishwasher after a cycle.
If water pools at the bottom of the tub after every cycle, the drain hose may be kinked or the check valve may be stuck. Pull the dishwasher out from the cabinet to inspect the hose, or call a technician if the issue persists after cleaning.
Ongoing Maintenance Tips
Keeping your dishwasher clean between deep cleanings requires just a few habits:
- Scrape plates before loading: You do not need to pre-rinse, but remove large food scraps to reduce filter buildup
- Run hot water at the kitchen sink before starting the dishwasher so the first fill cycle uses hot water immediately
- Leave the door ajar after each cycle to let moisture escape and prevent mildew growth
- Clean the filter every two weeks if you run the dishwasher daily, or monthly for lighter use
- Use a rinse aid to reduce mineral spotting, especially if you have hard water above 7 grains per gallon
A clean dishwasher uses less energy, cleans more effectively, and lasts longer. Thirty minutes once a month is a small investment that prevents expensive repairs and keeps your dishes coming out spotless. Now that you know how to clean a dishwasher properly, there is no reason to let buildup compromise your machine’s performance.
