How to Deep-Clean Your Dishwasher

Your dishwasher cleans dishes, but nobody cleans the dishwasher—until it starts smelling sour or your dishes come out cloudy. Hard water deposits, grease residue, and food particles accumulate in the spray arms, filter, and corners where you never see them. A deep clean takes about an hour of actual work spread across two cycles, and the result is a machine that runs quieter, dries better, and keeps your dishes genuinely clean instead of just rearranged. This isn't maintenance you need to do monthly, but two or three times a year keeps everything working right.

1. Clear It Out Completely. Remove all dishes, racks, and utensil baskets. Look inside with a flashlight. You're looking for obvious debris—bits of food, broken glass, anything lodged in the corners or spray arm holes. Pull out anything you find with your fingers or a small brush. An empty machine is the only way to see what actually needs cleaning.
2. Find and Free the Filter. Locate your dishwasher's filter, usually at the bottom center where the spray arm meets the tub floor. Most filters twist counterclockwise out of their housing. Pull it straight up and out. Hold it up to the light. You'll see matted food particles, grease, and mineral buildup. If the filter is badly clogged, soak it in hot water with a drop of dish soap for ten minutes, then scrub it gently with an old toothbrush. Rinse it thoroughly under running water until the water runs clear.
3. Unblock Every Spray Hole. The spray arms have small holes underneath that spray water over the dishes. These holes clog with mineral deposits and hardened food particles. Remove the spray arms by unclipping or unscrewing them from their center posts. Hold each arm up to light and look through the holes—you should see clear light. If you see white crusty deposits or the holes look blocked, use a toothpick or straightened paper clip to carefully clear each hole. Push from the inside out. Run your finger over the top of the arm to feel for any rough spots that indicate blockages. Rinse the arm under running water.
4. Scrub All Interior Surfaces. Use a damp microfiber cloth or old terrycloth to wipe the inside walls, especially the top corners and along the rubber seals where moisture promotes mold growth. Work your way around the entire tub. Pay special attention to the door frame—mineral deposits and old food particles hide there. If you see mold or mildew (black or green spots), spray vinegar directly on the spots and let it sit for five minutes, then wipe clean. Don't use bleach on rubber seals; it breaks down the material.
5. Load the Vinegar Weapon. Return the filter to its housing and reinstall the spray arms in their original positions. Pour two cups of white vinegar into a microwave-safe bowl or measuring cup. Place this container upright on the bottom rack of the dishwasher, or if your model has a dedicated vinegar dispenser in the door, use that instead. The vinegar will distribute throughout the machine during the cycle and dissolve mineral deposits, cut grease, and kill odor-causing bacteria.
6. Start the Long Hot Cycle. Close the door and select the longest, hottest cycle your dishwasher offers. Most machines call this the 'heavy' or 'pots and pans' cycle. The heat and water pressure combined with the vinegar will dissolve years of mineral buildup from the spray arms, tub walls, and internal plumbing. Let it run through completely. This takes about two hours depending on your machine. You'll notice the smell of vinegar—that's the cleaning happening.
7. Check for Loosened Deposits. When the cycle finishes and the tub is cool, open the door. Remove the bowl or cup that held the vinegar. Look at the bottom of the tub and the filter area—you may see a white or gray sediment or film. This is mineral deposit that the vinegar loosened. Don't worry; the baking soda cycle will handle it. Wipe out any loose sediment with a paper towel.
8. Scatter the Baking Soda. Sprinkle one cup of baking soda evenly across the bottom of the empty dishwasher. Unlike the vinegar, which goes in a container, the baking soda sits directly on the tub floor. It will react with any remaining vinegar residue, creating a light fizzing action that lifts deposits and odors. Baking soda also polishes the interior surfaces and acts as a natural deodorizer.
9. Let Baking Soda Work Its Magic. Select another hot cycle, but not the longest one this time—a regular wash cycle is fine. The baking soda will dissolve and distribute through the spray arms, filter, and entire tub. You'll see a light cloud of baking soda residue during the cycle, which is exactly what you want. Let it complete.
10. Verify It's All Clean. When the cycle finishes, open the door and wipe the entire interior with a clean, damp cloth. You're removing any residual baking soda powder and confirming that mineral deposits are gone. Run your finger along the bottom edges and around the filter housing—it should feel smooth and clean, not gritty. If you see any remaining white deposits, they're likely in the spray arm holes; use a toothpick to clear them.
11. Flush Away All Residue. Close the door and run one more quick rinse or light wash cycle with nothing inside the machine. This clears away any remaining baking soda residue that might otherwise transfer to your next load of dishes. It's a short cycle and uses minimal water, so it's not wasteful. When it finishes, your dishwasher is truly clean.
12. Restore and Run Your First Load. Replace any removable parts—silverware basket, utensil racks, adjustable shelves—back into the machine exactly as they were. Run your first load after the deep clean on a regular cycle. You'll immediately notice the difference: dishes come out drier, glass looks clearer, and the machine runs quieter because the spray arms can now spin freely.