Your Dishwasher float valves control the amount of water used inside the automatic dishwasher during the wash and rinse cycles when dishes are being cleaned and rinsed. The problem that often happens is when the valve malfunctions and there is either a lot of excess water or too little water. If it is the first problem, the water tends to overflow, making a mess of your kitchen floor and not getting dishes clean. If the amount of water is too low, the dishes will not be cleaned and the dishwasher seals may start to dry out.
Modern appliances, like automatic dishwashers, are designed to be efficient in performing the work they were built to do. The system of timers, dispensers and float valves all work together to achieve a specific task. When a problem arises, there are a few items to check before calling a repairman. First, make sure your dishwasher is empty of dishes. Next, look to see if something is blocking the area around the dishwasher float valve. If a utensil or other item is stuck underneath, it will interfere with the operation inside the valve. If the float inside the valve does not rise to cut off the flow of water in time, it will overflow and cause a mess.
If the float is blocked, remove whatever is causing the blockage and make sure the operation of the float is working by running the empty dishwasher on a rinse cycle to see if it operates as expected. If so, then then load the dishwasher with dirty dishes, add detergent and use as normal, keeping an eye out for any malfunctions. Often, problems caused by a simple blockage of the float cup inside the valve will be solved when the blockage is removed.
Conclusion: So, if you have checked the float valve, removed any obstruction and still have problems, it may be something within the dishwasher float valve itself or something else effecting the valve. If so, it may be time to have a professional look at the appliance to see what is happening. If the valve is broken inside, it may need to be replaced. It is a good idea to tell the repair technician what you have tried and whether it worked or not. Before a repairman comes, make sure he has enough working space inside the dishwasher by removing dirty dishes and having a towel in place in case of leaks is a great idea.