How to Clean Hard Water from a Dishwasher

Hard water deposits can shorten the life of dishwasher parts.

Hard water contains minerals such as calcium and magnesium. While no health threat comes from hard water minerals, according to the University of Washington in St. Louis' website, they can leave insoluble deposits that are difficult to clean, such as rings of soap scum around bathtubs and spots or scales on dishes. As deposits build up in pipes and appliances such as dishwashers, they can reduce the efficiency of heat transfer and impede water flow. Dishes coated with hard water mineral deposits can cause food to cook unevenly or slowly. Appliance parts and pipes coated with scales need replacing more often than non-scaly parts.

Things You'll Need

• Vinegar or citric acid crystals
• Measuring cup
• Soluble liquid rust remover
• Rubber gloves
• Dishwasher detergent

Instructions

Use Vinegar or Citric Acid Crystals

1. Remove all dishes and utensils from the dishwasher.

2. Set the dishwasher to a regular wash cycle.

3. Press the dishwasher's start button.

4. Add vinegar or citric acid crystals to the detergent compartment after the first cycle starts and the appliance fills with water. Citric acid crystals and vinegar are useful for hard water minerals such as calcium and iron.

5. Allow the full cycle to run.

Use Rust Remover

1. Empty the dishwasher.

2. Set the dishwasher to the rinse cycle.

3. Add 1/2 cup of soluble liquid rust remover to the dishwasher as it fills with water. Soluble liquid rust remover is useful for iron deposits left behind by hard water.

4. Allow the cycle to complete.

Use Dishwasher Detergent

1. Put on rubber gloves.

2. Scrub the dishwasher with dishwasher detergent that normally you would use in wash cycles. Pay special attention to stains. This method is useful for regular cleanings.

3. Rinse the detergent using cups of hot water, or set the dishwasher to the rinse cycle and allow it to run.

Tips & Warnings

• If scaling on appliances, tubs and dishes is a consistent problem in your home, consider installing a water softener. It will help protect appliance parts and avoid difficult stains.

• Keep all products used to clean the dishwasher away from pets and children because they may be toxic.

References

• Washington University in St. Louis: Water Hardness; Inorganic Reactions Experiment
• Michigan State University Extension: Dishwasher-Cleaning