1. Dirty or clogged filter

A clogged filter is one of the most common reasons dishwashers stop cleaning effectively. The filter traps food particles during the wash cycle, but over time it becomes clogged with debris. When the filter is blocked, water can't circulate properly and food particles get redistributed onto dishes instead of being washed away.

Most dishwasher filters are located at the bottom center of the tub, though placement varies by model. If your dishes feel gritty after washing or you notice food residue that wasn't there before, check the filter first.

Remove the filter according to your owner's manual — most twist or lift out easily. Rinse it under hot water and use a soft brush or sponge to gently scrub away food particles and buildup. Avoid harsh scrubbing that could damage the mesh. Then reinstall the filter securely before running another cycle.

If your run your dishwasher daily, aim to clean your dishwasher filter every month to avoid issues. For less frequent us, every two to three months should suffice. Regular filter maintenance prevents most cleaning problems and keeps the dishwasher running efficiently.

2. Wrong detergent or incorrect amount

Using the wrong type or amount of detergent causes cleaning problems and can leave film on dishes. Only use detergent specifically labeled for automatic dishwashers. Regular dish soap creates thick foam that overflows through the door and doesn't clean dishes properly.

Pre-measured tablets and pods work better than powder, liquid, or gel detergents at reducing film buildup. They contain the correct amount of detergent and dissolve at the right time during the cycle. If you use powder or liquid, measure carefully — too little won't clean effectively, while too much leaves residue.

Store detergent in a cool, dry place with the container tightly closed. Detergent that absorbs moisture becomes less effective. Old detergent also loses cleaning power, so replace it if you've had the same container for more than a year.

If possible, add rinse aid to the dispenser. Rinse aid helps water sheet off dishes instead of forming droplets, which reduces spots and film from hard water minerals. It's particularly important if you have hard water.

While some swear by adding a drop of dish soap to the dishwasher to boost cleaning power, this is a bad idea. Regular dish soap is designed to create lots of suds, and even a small amount can cause excessive foaming, overflow, and potential damage to your dishwasher.

3. Improper loading

How you load the dishwasher directly affects cleaning performance. Dishes that overlap, face the wrong direction, or block the spray arms won't get clean no matter what detergent or cycle you use.

Place dishes at an angle facing the center and downward so water reaches all surfaces. Concave items like bowls, cups, and mugs should be face-down. Flat items like plates and cutting boards should angle toward the spray arms, not away from them.

Don't overcrowd the dishwasher. Overlapping dishes block water from reaching surfaces, and tightly packed loads prevent proper water circulation. Leave space between items so spray can reach all surfaces.

Also, don't block the detergent dispenser. If the dispenser door can't open fully during the cycle, detergent won't release properly and dishes won't get clean. Check that no large items in the bottom rack interfere with the dispenser on the door.

4. You live in a hard water area

Hard water contains high levels of minerals like calcium and magnesium that interfere with dishwasher performance. These minerals prevent detergent from working effectively and leave behind chalky white residue on dishes and glassware.

If you notice cloudy film on glasses, white spots on dishes, or a buildup inside your dishwasher, hard water is likely the culprit. The minerals in hard water bind with detergent, reducing its cleaning power and preventing it from properly dissolving grease and food particles.

Consider adding a water softening agent or dishwasher salt if your machine has a built-in water softener. This regenerates the softening system and helps counteract mineral buildup.

For areas with extremely hard water, installing a whole-home water softener provides the most comprehensive solution.

5. When to call for service

If you've checked all five issues and your dishwasher still isn't cleaning properly, there may be a mechanical problem. Worn spray arms, a failing pump, or a malfunctioning heating element require professional repair.

Signs you need service include unusual noises during operation, water not draining properly after cycles, or the dishwasher not filling with water. These indicate problems beyond routine maintenance.

Always consult your owner's manual for model-specific troubleshooting before calling for service.