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Rust spots on cutlery after washing in the dishwasher
AEG Support

Rust spots on cutlery after washing in the dishwasher

If rust spots on cutlery after washing in the dishwasher, refer to the suggestions below for step by step instructions.

'Stainless steel' which is not stainless:
  • Do not leave cutlery coated in food waste inside the dishwasher.
  • Rinse the cutlery before placing it in the dishwasher or start the dishwasher’s rinse cycle if the dishwasher does not need to be started immediately.
  • Rust on stainless steel can be removed using a steel polish.
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Steel known as ‘stainless steel’ is very resistant to rust.

  • The metal forms a protective layer on the surface, called an 'oxide layer'.
  • If the surface is damaged, e.g. when a knife is scratched, oxygen from the surroundings will immediately create a new protective layer.
  • However, some substances can damage and break through the protective layer without allowing it to regenerate.
  • These include strong and acidic foods such as salt, lemon, vinegar, ketchup and mayonnaise.
  • Dishwashing detergents containing acids or chlorine can also break down the protective layer.
Crockery or cutlery which has non-stainless parts:

If cutlery or other stainless steel tools have been exposed to fruit acids, acetic acid, lactic acid or salt for an extended period of time, the rust can then spread. For example, cheese or egg slicers with a corroded cutting string. 

  • Do not put these items or parts in a dishwasher.
The plastic coating on the baskets is damaged:

The plastic coating on the dishwasher basket is very strong.

  • It is resistant to the chemicals in dishwashing detergents and impacts. However, it can be damaged mechanically, by cuts and abrasions on the plastic coating, such as caused by long sharp blades being put into the basket.
  • When there is a hole in the plastic coating, rust will be released from the metal framework of the baskets.
  • Replace the baskets to resolve this issue.
Water pipes made from different metals:

The water pipes leading to the dishwasher can be made from a variety of materials, such as galvanized steel, copper and brass.

  • The different metals can react with each other, causing corrosion to form in the pipes. The corrosion will eventually lead to rust in the water leading to the dishwasher.
  • Contact a plumber and ask them to check the water supply to the dishwasher.
Floating rust:

When there is rust in a dishwasher, it “floats” around during the washing cycle. Hence the name “floating rust”.

  • Floating rust can can settle anywhere in the dishwasher.
  • This can cause brown spots on porcelain, which resemble rust. This is floating rust, which has “landed” on a plate, for example.
  • Floating rust which has settled inside the dishwasher parts must be removed using citric acid powder or appliance cleaner.
  1. Place citric acid powder or machine cleaner in the detergent dispenser and start the intensive cycle.
  2. When the cycle has finished, leave the dishwasher door open until the inside of the dishwasher is completely dry.
  • Floating rust which has settled on crockery and cutlery can be removed using a steel polish.