Model KUD802 top rack not cleaning

SOURCE: Top rack remains dirty

spin the top rotary arm to make sure it spins freely also take it off to see if its blocked (run it under tap) check all other filters too and when you load dishes make sure they do not obstuct top rotary arm if none of this works then it's time for an engineer im affraid good luck

SOURCE: kitchen aid dishwasher doesn't clean dishes in the top rack

replace the top spray arm and it should work ok again

SOURCE: Kitchenaid, new dishwasher, stopped cleaning top rack dishes

The problem most people encounter with dishwashers is a simple inability to get the dishes clean. There might be stuck-on food or residue from the detergent. A water pressure problem may be the culprit. You may need to replace the water intake valve. Another common problem is mineral build-up. If your house has hard water, the mineral build-up can clog the water jets. Clear each jet with a wire or pin, and run an empty load with some vinegar in the detergent dispenser about once a month.

Sometimes, the dishwasher has problems draining properly. There could be a clog in the drain hose, or a problem with the pump. It's also possible that the dishwater is getting too sudsy, and sensors in the washer aren't detecting the soap foam as water. This causes it to shut down the drain cycle too early. Just use less detergent.

SOURCE: Upper rack dishes not cleaning well

Yes, run an empty load with 1/4 cup vinegar. It sounds like there is mineral build up in the arm. Try to take the arm apart that supplies water to the top rack of the dishwasher. You can soak this in vinegar water once removed.

SOURCE: will not clean dishes on the upper rack

Make sure you get water to the dishwasher. Check to see if the water shut-off valve (located under the sink) is open. If you get water to the dishwasher, but there is still no water inside during the fill cycle, the problem might be with a faulty water valve (located at the bottom of the dishwasher, behind the kick panel, on either side), in which case replace the water valve.

If there is not enough water, the dishes would not get cleaned. This could be caused by a partially closed water shut-off valve (located under the sink), or a faulty dishwasher water valve (located at the bottom of the dishwasher, behind the kick panel, on either side).

There is usually two, sometimes three spray arms in a dishwasher. Make sure there is no debris blocking the holes inside each spray arm.