What Causes Rust in a Dishwasher?


What Causes Rust in a Dishwasher?

It’s annoying when you open your dishwasher to find rust in the interior or on your dishes, but the problem might not be as serious as it seems. Rust in a dishwasher can come from the water supply, from the dishwasher itself, or from the utensils you’re washing. Whatever the cause, you can prevent those nasty red or brown stains from reappearing.

Iron in the Water
If a reddish-brown film regularly coats your dishwasher interior or dishes, iron in your water supply is probably the reason. In some areas, the local water naturally contains iron oxide, which is deposited in the machine during the wash cycle. Another source of iron in your water could be rust from old galvanized pipes in your home plumbing.

Using the full amount of dishwasher detergent and a rinse aid helps prevent rust stains from iron in your household’s water. If the problem doesn’t go away, remove all the dishes and try citric acid crystals or a specialized dishwasher cleaning product for removing rust stains. A plumber can also fit rust filters or iron removal equipment to your water supply.

Rusty Interior
Though the inner surface of your dishwasher isn’t likely to rust, the racks can suffer this problem after a few years of use. When the racks lose their finish, the metal underneath becomes exposed to water and turns rusty. Sometimes you can see the rust, or you might only see blisters on the finish. Beneath the blisters are patches of rust.

Contact your dishwasher’s manufacturer and ask if they supply touch-up liquid, which is like fingernail polish. Before applying the liquid, sand down the area to be treated to bare, clean metal.

Rust on Metal Items
Metal items like cutlery and even pots and pans can turn rusty after washing in a dishwasher. Stainless steel knives, forks, and other cutlery develop rusty pits on their surfaces after prolonged exposure to water.

If this is a problem for you

  • don’t use the rinse and hold option
  • remove and dry metal items immediately that the dishwasher cycle has finished
  • check that you’re using the right amount and type of detergent
  • check that you’re putting the dishwasher through the correct cycle after adding salt, according to the manufacturer’s instructions.

Preventing those red and brown stains from rust in a dishwasher is a piece of cake when you know what’s causing them. It might be a simple fix, or you might need professional help to find a permanent solution, but you can look forward to clean, rust-free dishes.

For answers to your questions, contact the Pink Plumber today.