The most common dishwasher fault is a clogged drain, causing water to sit at the bottom. Learn how to fix it yourself before calling a technician and avoid costly repairs.
Dishwasher Not Cleaning? Common Causes and How to Fix It
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. Most people assume it’s broken beyond repair, but 8 out of 10 times, it’s something simple you can fix without calling a technician.
The dishwasher filter, a component that traps food particles to prevent clogs in the drain and spray system is the #1 culprit. If it’s clogged with grease, coffee grounds, or bits of pasta, water can’t circulate properly. It’s easy to check—just pull out the bottom rack, locate the filter near the drain, and rinse it under warm water. No tools needed. Another common issue is the spray arm, the rotating arm that shoots water onto dishes. If it’s blocked by food debris or broken from wear, it won’t spin or spray evenly. Take it off, clean the holes with a toothpick, and make sure it spins freely by hand.
Don’t overlook the dishwasher detergent, the cleaning agent specifically formulated for automatic dishwashers. Using the wrong kind—like hand soap or too much powder—can create suds that stop the machine from working right. Pods work best for most homes. Also, check if the water is hot enough. If your water heater is set below 120°F, the dishwasher won’t clean effectively. Run the kitchen tap until the water’s hot before starting a cycle.
Other problems? A faulty water inlet valve, the part that lets water into the dishwasher might not be opening fully, or the pump, the motor-driven component that circulates water through the system could be worn out. These are harder to fix on your own, but they’re rare compared to filter or spray arm issues. If you’ve cleaned everything and it’s still not working, it’s time to look at the control board or call a local expert.
Most of the fixes here take less than 15 minutes and cost nothing. You don’t need to replace the whole machine just because your glasses still have food stuck on them. The posts below cover real cases from South Shields homes—like how a blocked filter caused a dishwasher to leave grease on plates for months, or how a broken spray arm was mistaken for a broken motor. You’ll find step-by-step checks, common mistakes people make, and when it’s smarter to repair versus replace. No fluff. Just what actually works.