How to Remove Lime Deposits in Dishwashers

What we call dishwasher "lime deposits" is not actually lime but a combination of substances left behind by hard water and detergents. In order to remove lime scale, we must understand that it is a combination of calcium carbonate and other minerals found in local water and the dirt and grease that is "floated off" dishes by detergents. This catches on surfaces, including water supply passages and dishes. Many chemicals that are strong enough to remove lime scale can also damage internal parts or surfaces.

Step 1

Change the detergent you use. Powdered dishwasher detergent is more efficient in removing grease and oil than gels. Decreasing the gunk left on surfaces may help slow lime scale buildup.

Step 2

Put a quart of vinegar or lemon juice in the bottom of an empty dishwasher and run it up to the "dry" cycle once a month to keep up with accumulating scale. Extended exposure to mild acid and hot water dissolves most scale.

Step 3

Clean circulator arms with vinegar or lemon juice and a vegetable brush or toothbrush. Let the acid sit on the scale before scrubbing. Use a needle or hat pin to pierce clogged holes, then rinse by running a cycle with vinegar.

Step 4

Use plain salt or baking soda to scour surfaces with a sponge or rag. Rinse with boiling water or run a cycle with an empty dishwasher. Do not run the dry cycle.