Repair Riot

Dishwasher Leaving Rust Spots on Cutlery

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Quick answer

Rust spots on cutlery from your dishwasher are often caused by hard water or a faulty detergent dispenser. Check your water hardness and ensure you're using the right detergent. Clean the dispenser and rinse aid to prevent future spots.

Confirm the symptom

Tools and prep

Step-by-step troubleshooting

  1. Check Water Hardness
    Do: Test your home’s water hardness using a test kit from a hardware store.
    Observe: High mineral content in the water.
    Means: Hard water can leave mineral deposits that oxidize and appear as rust spots.
    Next: Use a water softener or add vinegar to the dishwasher.
  2. Inspect Detergent and Rinse Aid
    Do: Check the type and amount of detergent and rinse aid being used.
    Observe: Using too much detergent or incorrect type can leave residues.
    Means: Improper detergent can cause mineral deposits and spots.
    Next: Switch to a high-quality detergent and rinse aid designed for hard water.
  3. Clean the Detergent Dispenser
    Do: Remove the dispenser and soak it in a mixture of equal parts water and vinegar for 30 minutes.
    Observe: Mineral buildup dissolves and dispenser is clean.
    Means: A clean dispenser ensures proper detergent and rinse aid distribution.
    Next: Reinstall the dispenser and run a test cycle.
  4. Clean the Dishwasher Interior
    Do: Run an empty dishwasher cycle with a cup of vinegar or a dishwasher cleaner on the hottest setting.
    Observe: Suds and residue are removed from the interior.
    Means: A clean interior prevents mineral buildup and spots.
    Next: Wipe down the interior with a soft cloth after the cycle.
  5. Check for Rust in the Dishwasher
    Do: Inspect the dishwasher’s interior for any signs of rust or corrosion.
    Observe: Rust spots on the dishwasher’s interior or components.
    Means: Rust inside the dishwasher can transfer to cutlery.
    Next: Replace any corroded parts or the entire unit if necessary.
  6. Adjust Cutlery Placement
    Do: Rearrange cutlery to ensure it is not touching the dishwasher’s interior or other utensils.
    Observe: Cutlery is spaced out and not in contact with metal surfaces.
    Means: Proper spacing prevents direct contact that can cause rust transfer.
    Next: Run a test cycle to see if spots persist.

Common causes

CauseLikelihoodDifficultyPart often needed
Hard Water
Mineral deposits from hard water can oxidize and appear as rust spots on cutlery.
CommonEasyWater softener or vinegar
Improper Detergent
Using the wrong type or excessive detergent can leave residues that attract minerals.
CommonEasyHigh-quality detergent
Faulty Rinse Aid Dispenser
A clogged or malfunctioning rinse aid dispenser can lead to poor rinsing and mineral buildup.
SometimesEasy–MediumRinse aid dispenser
Rust Inside Dishwasher
Corrosion inside the dishwasher can transfer to cutlery during the wash cycle.
SometimesMediumDishwasher parts or unit replacement
Incorrect Cutlery Placement
Cutlery touching the dishwasher’s interior or other utensils can cause rust transfer.
SometimesEasyCutlery rack adjustment
Low Water Temperature
Insufficient water temperature can prevent proper cleaning and rinsing, leading to mineral deposits.
RareMediumWater heater adjustment
Overloading the Dishwasher
Overloading can restrict water and detergent flow, leading to poor cleaning and spots.
RareEasyNone

Parts matching

If you need to replace parts, look for these common components:

When purchasing parts, ensure they are compatible with your dishwasher model.

When to call a professional

FAQ

Can I use regular dish soap in my dishwasher?

No, regular dish soap is not designed for dishwashers and can create excessive suds and residue. Use a detergent specifically formulated for dishwashers.

How often should I clean my dishwasher?

Clean your dishwasher at least once a month with a vinegar or dishwasher cleaner cycle to prevent mineral buildup and maintain performance.

What is the best way to test water hardness at home?

Use a water hardness test kit available at hardware stores or online. Follow the instructions provided with the kit to determine the hardness level of your water.

Can I use lemon juice instead of vinegar to clean my dishwasher?

Yes, lemon juice can be used as a natural alternative to vinegar for cleaning your dishwasher. Run an empty cycle with a cup of lemon juice on the hottest setting.

Why do my dishes still have spots after using rinse aid?

Spots may still occur if the rinse aid dispenser is clogged or the rinse aid level is too low. Clean the dispenser and ensure it is filled with the correct amount of rinse aid.