5 Reasons Your Dishwasher Isn't Cleaning Dishes Properly

A dishwasher that leaves your dishes dirty, spotty, or with food residue can be incredibly frustrating. At Appliance Pro Care, we've diagnosed and repaired countless dishwashers throughout Greater Boston and the South Shore, and we've found that most cleaning issues can be traced back to a handful of common problems.

1. Improper Loading Techniques

How you load your dishwasher significantly impacts its cleaning performance. Overloading, nesting items, or blocking the spray arms can prevent water from reaching all surfaces.

Solution: Follow these loading best practices:

• Place items facing downward so water can reach inside
• Don't overcrowd the racks
• Avoid nesting bowls or cups
• Ensure spray arms can rotate freely
• Place heavily soiled items on the bottom rack facing the center

2. Clogged Spray Arms

The spray arms distribute water throughout your dishwasher. If the small holes in these arms become clogged with food particles, mineral deposits, or debris, water distribution will be compromised.

Solution: Remove the spray arms (consult your owner's manual for instructions) and clean the holes with a small piece of wire, toothpick, or pipe cleaner. Rinse thoroughly before reinstalling.

3. Dirty or Clogged Filters

Most modern dishwashers have a filtration system at the bottom that prevents food particles from recirculating onto your clean dishes. If these filters become clogged, cleaning performance suffers.

Solution: Remove and clean the filters regularly (weekly for heavy use, monthly for lighter use). Rinse under hot water and use a soft brush to remove stubborn debris. Some filters are dishwasher-safe and can be run through a cycle on the top rack.

4. Water Temperature Issues

Dishwashers need hot water—typically 120-125°F (49-52°C)—to clean effectively and activate detergent properly.

Solution: Before starting your dishwasher, run hot water at the kitchen sink until it's hot to ensure the dishwasher fills with hot water. Check your water heater settings if water temperature is consistently an issue.

5. Detergent and Rinse Aid Problems

Using the wrong type or amount of detergent, or running out of rinse aid, can lead to poor cleaning results and spotty dishes.

Solution:

• Use detergent specifically formulated for dishwashers
• For hard water areas, use a detergent with water softeners
• Don't use too much or too little detergent
• Keep the rinse aid dispenser filled
• Consider using a dishwasher cleaner monthly to remove buildup