Dishwasher Not Cleaning Dishes? Here’s Why

A dishwasher that leaves dishes dirty, cloudy, or still greasy after a full cycle is one of those problems that's easy to ignore at first—until it isn't. At Purcell Appliance Center, we hear this complaint regularly, and in most cases the fix is simpler than people expect. Here's what's most likely causing the problem and what to check before you call.

Why Is My Dishwasher Not Cleaning Properly?

Most cleaning problems come down to water not reaching the dishes correctly, a buildup of mineral deposits, or a detergent issue that's easy to overlook. Here are the most common causes.

• Dirty or clogged spray arms. The spray arms rotate and shoot water onto your dishes throughout the cycle. When the small holes along the arms get clogged with food debris or mineral deposits, water distribution becomes uneven and dishes don't get clean.
• Failing circulation pump. The circulation pump is responsible for pushing water through the spray arms with enough pressure to clean effectively. When it starts to fail, water pressure drops and cleaning performance suffers noticeably.
• Hard water buildup. Champaign area water is moderately hard, and over time mineral deposits can coat the interior of the dishwasher, clog the spray arms, and leave a white film on glassware and dishes.
• Clogged or dirty filter. Most modern dishwashers have a removable filter at the bottom of the tub that traps food particles. When it gets too full, water can't circulate properly and food residue gets redistributed onto dishes instead of draining away.
• Detergent problems. Old detergent, the wrong type, or too much or too little can all affect cleaning results. Pods, powder, and gel each perform differently depending on your water hardness and machine type.
• Low water temperature. Dishwashers need water at around 120°F to dissolve detergent and cut through grease effectively. If your water heater is set too low or the dishwasher's heating element is failing, cleaning performance drops.

Pro Tip:
Run your kitchen faucet until the water is hot before starting the dishwasher. This ensures the first fill pulls in hot water instead of cold, which gives detergent a better chance to activate from the very beginning of the cycle.

Simple Things to Check Before You Call

Before scheduling a repair, a few quick checks can rule out easy fixes. Many dishwasher cleaning problems can be resolved without a technician.

• Remove and rinse the spray arms. Pull them off (they typically unscrew or unclip) and hold them under running water. Use a toothpick or small brush to clear any blocked holes. Reattach them and make sure they spin freely.
• Clean the filter. Remove the filter from the bottom of the tub, rinse it under warm water, and use a soft brush to clear any buildup. Refer to your owner's manual for the location and removal method on your specific model.
• Run a cleaning cycle with a dishwasher cleaner. Products like Affresh or a cup of white vinegar placed in the bottom of the tub can help dissolve hard water deposits and refresh the interior. Run an empty hot cycle monthly to keep buildup in check.
• Check your detergent. Make sure you're using fresh detergent and the right amount for your water hardness. In harder water areas, using a rinse aid alongside your detergent can significantly improve results.
• Load dishes correctly. Overcrowding or blocking the spray arms with large items prevents water from reaching everything. Make sure nothing is obstructing the rotation of the spray arms before running a cycle.
• Confirm the water temperature. Run your kitchen faucet and check that hot water arrives quickly at the sink. If hot water takes a long time to reach the kitchen, your dishwasher may be filling with lukewarm water.

Pro Tip:
Clean your dishwasher filter once a month. It takes about two minutes and is one of the most effective ways to maintain cleaning performance and prevent odors.

Signs It's Time to Call a Technician

If dishes are consistently coming out dirty after cleaning the spray arms and filter, the problem likely goes deeper. Call for service if you notice any of the following.

• Dishes are dirty on every cycle regardless of how you load them. Consistent poor results after basic maintenance usually point to a pump, water inlet, or heating element issue.
• You hear unusual noises during the wash cycle. Grinding, humming, or rattling sounds can indicate a failing circulation pump or debris caught in the pump assembly.
• There is standing water at the bottom after the cycle. Poor cleaning and drainage problems often occur together, and a technician can diagnose both on the same visit.
• Glassware has a permanent hazy film that won't come off. Severe hard water etching can permanently cloud glassware, but a technician can assess whether the dishwasher itself is contributing to the problem.
• The interior smells bad even after cleaning. Persistent odors can indicate a drainage issue or buildup in areas you can't easily reach, such as the pump or internal hose lines.

Same-day service is available. A dishwasher that isn't cleaning properly often has a straightforward fix—and the sooner it's addressed, the less buildup accumulates inside the machine.

Call 217-352-7500

Pro Tip:
If you have hard water, consider adding a rinse aid dispenser refill to your routine. Rinse aid helps water sheet off dishes instead of pooling, which significantly reduces spotting and film on glassware.

Repair vs. Replace: What Makes Sense?

Most dishwasher cleaning repairs are affordable and worth making, especially on machines that are less than 10 years old. Replacing a spray arm, cleaning the pump, or addressing a water inlet issue is typically a straightforward job.

• Spray arm and filter issues are almost always worth fixing. These are low-cost repairs or simple maintenance tasks that restore full cleaning performance quickly.
• Circulation pump replacement is a moderate repair. On most dishwashers, pump replacement is still well within the range where repair makes financial sense compared to buying new.
• Age and condition matter. If your dishwasher is over 10 years old and showing multiple problems at once, comparing repair cost to the price of a new unit is a reasonable conversation to have.
• We carry in-stock dishwashers. If replacement is the right call, we have models available now with professional installation so you're not hand-washing dishes any longer than necessary.

When Your Dishwasher Works, the Kitchen Runs Smoother

A dishwasher that doesn't clean is almost worse than not having one at all—you're using water and energy without getting results. At Purcell Appliance Center, we diagnose and repair dishwasher problems quickly, often the same day you call. Our technicians are experienced with all major brands and can identify most cleaning issues on the first visit.

Serving Champaign, IL and the surrounding area, we're your local resource for honest appliance repair at a fair price. Call 217-352-7500 or stop in today and let our team help get your dishwasher back to doing its job.