There could be several reasons why your dishwasher left spots on your dishes. Here are some common issues and solutions:
Hard water: Hard water contains a high concentration of minerals like calcium and magnesium, which can leave spots on dishes. Consider using a water softener or adding a dishwasher rinse aid to reduce the impact of hard water.
Improper detergent: Using the wrong type of detergent or not using enough can lead to poor cleaning results. Make sure you're using a high-quality dishwasher detergent that is suitable for your dishwasher and water hardness.
Overloading the dishwasher: If you overload the dishwasher, it may not be able to spray water evenly, leading to areas with leftover food residue and spots. Load your dishwasher according to the manufacturer's guidelines, leaving enough space for water to circulate freely.
Incorrect dishwasher settings: Make sure you're using the appropriate cycle and temperature settings for your specific dishes and their level of soiling. Delicate items might need a different setting than heavily soiled pots and pans.
Pre-rinsing dishes: Modern dishwashers are designed to handle some food residue on dishes. Pre-rinsing dishes too thoroughly can actually hinder the dishwasher's cleaning performance. Scrape off excess food, but avoid pre-rinsing.
Old or clogged spray arms: Check the spray arms for clogs or damage. If they aren't spinning properly or are obstructed, they won't distribute water effectively.
Dishwasher maintenance: Regularly clean your dishwasher's filter, which can become clogged with food particles, affecting the dishwasher's performance.
Water temperature: Ensure your dishwasher is getting enough hot water. If your water heater temperature is set too low, it might not provide the necessary heat for effective cleaning.
Low-quality dishwasher: In some cases, the issue might be related to the dishwasher itself. If you consistently experience poor results despite trying various solutions, it could be time to consider upgrading to a more efficient model.
Try addressing these potential problems one by one to see if they improve the performance of your dishwasher. If you've tried several solutions and still face issues, it might be worth consulting a professional appliance repair technician for further assistance.