How to Decalcify a Dishwasher

Updated February 21, 2017

Calcium deposits leave white areas that look like chalk inside a dishwasher. Calcium deposits inside the dishwasher bake onto the heating element, door, racks and sides from the dishwasher's dry cycle. White calcium deposits left inside the dishwasher are the result of calcium carbonate found in the water supply. Some areas have a larger concentration of calcium carbonate in their water supply, making the problem worse. Removing calcium deposits inside the dishwasher improves the look of the dishwasher and improves its performance by clearing calcium build-up clogs in sprayer arms and drains.

Saturate a sponge with undiluted white vinegar. Wipe the interior of the dishwasher with the sponge. You can also fill a spray bottle with white vinegar and spray a heavy coating of vinegar inside the dishwasher. Allow the vinegar to soak into the calcium build-up for 10 to 15 minutes.

Fill a measuring cup with 4 cups white vinegar.

Place the measuring cup upright on the bottom rack with no other dishes or utensils in the dishwasher.

Turn the dishwasher on and run through a complete cycle. If calcium deposits remain, repeat the process.

Empty the dishwasher of dishes, pots, pans and utensils.

Fill the dishwasher's soap dispenser with citric acid crystals. Sprinkle 1/4 cup of citric acid on the bottom of the dishwasher.

Run the dishwasher through a full cycle. If calcium deposits are still present, repeat this method.

Add a commercially available decalcifying agent to your dishwasher. Decalcifiers are available in the form of rinse aids, sprays, crystals and plastic bottles with a cap that releases the cleaning agent as the cycle runs.

Place the decalcifying agent in the dishwasher according to the manufacturer's instructions. Decalcifying agents hang on the upper rack or are sprayed or sprinkled inside the dishwasher, or they rest in the utensil holder.

Turn the dishwasher on and allow it to run through a cycle. In the case of rinse aids, leave the basket inside the dishwasher for subsequent washes or refill the rinse aid dispenser as necessary for each washing. Add decalcifying sprays, bottles and crystals as part of a general maintenance schedule.


Clean the inside of the dishwasher regularly to avoid significant calcium build-up.


Do not scrape the calcium build-up off of the heating element, as you may damage it.

Things You'll Need

  • White vinegar
  • Sponge
  • Spray bottle
  • Measuring cup
  • Citric acid
  • Decalcifying agent
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About the Author

Sal Marco began writing professionally in 2009. He has written many online home improvement articles based on his more than 20 years of experience in the home improvement and building industries. He has worked as both part of a team and as a site supervisor. Marco has a Bachelor of Science in management science from Kean University.