The presence of black and white streaks on your dishes after they come out of the dishwasher can have several potential causes. Here are a few possibilities to consider:
Hard Water: Hard water contains high levels of minerals such as calcium and magnesium. When your dishwasher washes your dishes, the minerals can be left behind, resulting in white streaks or spots. These deposits are known as limescale. Hard water can also react with certain detergents, creating black streaks or marks on the dishes.
Detergent Residue: If you're using too much detergent or if your dishwasher isn't rinsing properly, it can lead to detergent residue on your dishes. This residue can appear as white streaks or spots.
Dirty Dishwasher or Spray Arms: Over time, your dishwasher's interior, including the spray arms, can accumulate debris, minerals, and detergent buildup. If the spray arms are clogged or not functioning properly, it can result in uneven water distribution during the wash cycle, causing streaks on your dishes.
Rust or Worn Rack Coating: If the protective coating on your dishwasher's racks is deteriorating or wearing off, it can expose the metal beneath. Rust or metal particles can then transfer onto your dishes during the wash cycle, causing black streaks.
Improper Loading: Dishwasher loading plays a role in ensuring proper water circulation and avoiding dish-to-dish contact. If dishes are stacked too closely or are touching each other, water may not reach all areas properly, leading to streaks or residues.
To address these issues, you can try the following solutions:
- Check and adjust your detergent usage according to the manufacturer's instructions.
- Use a dishwasher cleaner to remove any buildup or residue in the machine.
- Clean the spray arms and ensure they are free from blockages.
- Consider using a rinse aid designed for hard water to prevent mineral deposits.
- Examine the racks for any signs of rust or deterioration, and replace them if necessary.
- Practice proper loading techniques, allowing sufficient space between dishes.
If the problem persists despite these efforts, it may be beneficial to consult a professional appliance repair technician to diagnose and resolve the issue with your dishwasher.