Dishwasher Not Cleaning? Common Causes and Real Fixes

When your dishwasher, a household appliance designed to clean dishes automatically using water and detergent. Also known as a dishwashing machine, it’s meant to save time and effort—but when it stops cleaning properly, it becomes a daily frustration. You’re not alone. Many people assume a dishwasher that leaves food on plates is broken beyond repair. But in most cases, it’s a simple issue you can fix without tools—or even a technician.

The biggest culprit? A clogged spray arm, the rotating arm inside the dishwasher that shoots water onto dishes. Food bits, grease, or mineral buildup can block the holes. Take it out, rinse it under warm water, and poke each hole with a toothpick. If it spins freely after cleaning, you’ve solved half the problem. Another common issue is the dishwasher filter, a removable screen at the bottom that traps food debris. If it’s clogged, dirty water recirculates instead of fresh, clean water. Clean it monthly—some models even have a self-cleaning mode, but don’t rely on it.

Then there’s the detergent, the cleaning agent that breaks down grease and food residue. Using the wrong type—like hand soap or old, clumpy pods—can leave dishes grimy. Stick to dishwasher-specific tablets or powder. And don’t overload the machine. Pots stacked over spray arms? Plates blocking the rotor? That’s like putting a lid on a pot while boiling water—nothing gets clean.

Don’t overlook the dishwasher not cleaning signal: water temperature. If your water isn’t hot enough when it enters the machine, grease won’t melt. Check your water heater setting—it should be at least 120°F. Also, if your dishwasher has a built-in heater, a faulty one can cause the same problem. You won’t see it, but you’ll feel it on your plates.

And yes, the door seal matters. A worn or cracked gasket lets water escape before it can do its job. Run a quick test: close the door on a dollar bill. If you can pull it out easily, the seal is weak. Replacing it costs less than $30 and takes 15 minutes.

Some people blame the machine, but often the problem starts with how you load it. Forks facing down? Cups blocking spray? Dirty dishes pre-rinsed too hard? You’re fighting your own setup. Scrape food off, don’t rinse. Let the dishwasher do its job.

Below, you’ll find real fixes from people who’ve been there—whether it’s a broken pump, a faulty float switch, or just a forgotten rinse aid. No fluff. No guesswork. Just what actually works.