Incomplete or improper drainage can lead to stains on the dishes. If your dishwasher is newly installed, remove the knockout plug from the drain hose.
Another possibility is that the drain hose is clogged. This happens when the drain hose is also connected to a food disposer unit in a sink.
Activate the food disposer unit while the water is running in the sink to unclog and clear any food particles from the drain hose.
If dirty dishes appear untouched, especially on the top rack of the dishwasher, the problem may not be too much water but in fact too little. Water pressure differs from home to home and a Whirlpool washer requires pressure ranging from 20 to 120 psi.
If you suspect your dishwasher of low water pressure, open the faucet nearest the dishwasher and the place a 1 qt. container underneath the running water.
If the container takes more than nine seconds to fill, the water pressure is too low for a Whirlpool washer. Contact a plumber for a booster pump that can increase pressure to the washer.
If the problem isn't dirt leftover from pre-wash but instead a white or gray film that forms on dishes and cups, the problem may stem from the dish washing detergent. Prior to 2010, conventional detergents used phosphates to isolate dirt particles and soften water.
This practice contaminated water supplies because water treatment plants couldn't later separate the phosphates from the water. Many post-2010 detergents have substituted phosphates with other chemicals.
Unfortunately, these eco-friendly chemicals can leave a thick film on dishes. Switching to packs or tablets over powder or gel can minimize filming effects.
Orange stains that linger after washing can sometimes appear on plastic or ceramic containers, especially when washing dishes soiled from tomato based items such as sauces. Pre-rinse dishes and regularly use the rinse cycle and air drying options to minimize this type of staining.