It's always annoying when you fill a load of dishes in the dishwasher only to have them come out dirty once it's done. Instead of putting them up in the cabinets where they belong, you're now forced to re-wash them by hand. While some people may assume this is normal behavior for old dishwashers, there's usually an underlying problem. Once you identify and fix this problem, you can then use your dishwasher the way it's intended to be used.
Is The Water Hot Enough?
One of the reasons why dishwashers are more effective at cleaning dishes than using the sink is because of the water temperature they produce. Unlike faucets, most dishwashers spray out water that's around 140 degrees Fahrenheit, which is ideal for loosening up stubborn food particles and debris. If the water produced by your dishwasher is cooler than this, it simply won't clean as well. Unfortunately, testing the water temperature in your dishwasher isn't as easy as it seems. Once you open up the dishwasher, the water is gone, so how do you check it? The best way is to stick a laser thermometer in it immediately after it's done with a cycle. Check to see what it reads and if it's lower than 140 degrees Fahrenheit, you know you have a problem.
Sometimes the problem can be as simple as a broken or clogged spray arm. While your dishwasher is off, open up the door and inspect the spray device at the very top for any signs of damage. On rare occasions, food particles can get stuck inside the spray arm, preventing it from releasing water. If you find a clog, try to use a thin needle or ice pick to dig it out.
In the event the spray arm is completely broken or damaged, you may need to replace it. This is obviously a bit more difficult and complicated than removing a clog, so be prepared to spend more time on the problem.
Don't Overload The Dishwasher
Another common reason why dishwashers stop cleaning properly is because the owner overloads them. There's a fine line between filling a dishwasher up to save energy and placing too many items in it. When you place too many items in it, the water flow will be blocked, preventing some of the dishes from getting as clean as they should. Try to get into the habit of washing your pots, pans and other large items in the sink and placing everything else in the dishwasher.