There are a number of issues that can prevent a dishwasher from cleaning your dishes properly. However, a common issue is a lack of water. As an integral part of the washing cycle, if there isn't enough water flowing through the appliance during the cleaning and rinse cycle it can leave your dishes looking blotchy and feeling grimy. Fortunately, there are a couple of things you can do to see if a water issue is keeping your dishwasher from cleaning correctly.
A problem with the float can prevent the machine from filling up with enough water, which will prevent it from cleaning properly. As water fills the dishwasher, the float rises. Once it reaches its highest position, this sends a signal that there is enough water inside to run the cleaning cycle. Floats can get stuck in the raised position, causing the dishwasher to run without enough water to fully clean the dishes.
To check for this problem, start a cycle and open the door when you hear that the machine has stopped filling up with water. Locate the heating coil and ensure the water has either covered it or is very close. If this has not happened and the float is in the raised position, this is an indication that the float is not functioning correctly and needs to be repaired or replaced.
Clogged Spray Arm
Pre-washing isn't a required step before putting dishes inside the dishwasher. However, when you don't complete this process, you risk having some food debris settle in the machine. Much of this debris ends up inside the tiny holes that are lined along the spray arm. The spray arm is a long, spinning device that is responsible for spraying water on your dishes to clean and rinse them.
When the holes are clogged, the water can't flow out as it should. To check for this problem, remove the spray arm. Take thin hanging wire and gently thread it through the holes to remove any collected food debris. Once clean, replace the arm and repeat a wash cycle. This should solve your problem. If it does not, there could be an internal issue with the spray arm that would require a professional evaluation.
If you suspect there is a problem with your dishwasher, don't hesitate to contact an appliance repair specialist like Better Homes Appliance Service to help find the problem and the best solution for your machine.