How to Clean Your Dishwasher and Remove Mineral Buildup

Mineral buildup inside your dishwasher is invisible until it's not—hard water deposits coat the spray arms, clog the filter basket, and reduce water pressure until your dishes come out spotted and half-clean. You'll notice it when a load that should sparkle comes out dull, or when you hear the pump struggling. The good news is that mineral deposits respond quickly to acid and abrasive, and you likely have both in your kitchen already. A clean dishwasher runs quieter, dries faster, and actually gets your dishes clean again. This is maintenance you should do every month or two, depending on your water hardness. This job takes an hour and costs almost nothing. You don't need to disassemble anything or call a technician. Empty the machine, grab vinegar and baking soda, and run two back-to-back cycles while you do something else.

1. Spot the Mineral Culprit. Remove all dishes, racks, and loose items. Look at the filter basket at the bottom—if it's visibly covered in white, gray, or tan deposits, you've found your problem. Check the spray arms for mineral crust or blocked holes. Note any standing water at the bottom, which suggests a drain issue you'll address in this cleaning.
2. Liberate the Spray Arms. Lift out the cylindrical filter basket and rinse it under hot tap water. Use an old toothbrush or soft brush to scrub away loose deposits. For the spray arms, twist or lift them free (they usually come out without tools). Hold them up to the light and look through the spray holes—if they're blocked, use a straightened paper clip or toothpick to carefully poke through each hole. Rinse them clean and set aside.
3. Position the Acid Attack. Put the filter basket back in place, then reinstall the spray arms. Pour two cups of white vinegar into a dishwasher-safe bowl or measuring cup (not directly into the dispenser—you want it to release during the cycle, not sit in the dispenser). Place the bowl on the top rack where it won't tip during the cycle.
4. Dissolve Deposits Fast. Close the door, select the hottest water temperature available, and start a full wash cycle (not a short or quick cycle). The hot water and vinegar will dissolve mineral deposits throughout the tub, spray arms, and drain lines. This cycle does the heavy lifting; let it run completely without interruption.
5. Scour Away Stubborn Buildup. When the vinegar cycle finishes, sprinkle one cup of baking soda evenly across the bottom of the empty tub. Close the door and run another hot cycle without adding anything else. The baking soda acts as a mild abrasive to scour away stubborn deposits that vinegar alone couldn't dissolve.
6. Polish Hidden Corners. After the baking soda cycle finishes, open the door and look at the tub walls, floor, and spray arms. If you still see white or tan deposits, particularly around the edges or in corners, use a damp cloth or old sponge to manually wipe them away. The vinegar and baking soda will have loosened them enough to come off easily with light scrubbing.
7. Freshen the Door Seal. Mineral deposits also accumulate in the rubber seal that runs around the door. Use an old toothbrush or soft brush with a little vinegar to scrub along the gasket, getting into the crevices where water sits. Wipe it dry with a cloth. A clean gasket prevents mold and keeps your dishwasher running quietly.
8. Banish the Vinegar Smell. Run one final empty cycle on the shortest setting with hot water only. This clears any remaining vinegar smell and ensures no baking soda residue is left. Your dishwasher is now clean and ready to wash dishes again.