My dishwasher won't drain fully

you may have a part on your machine called a piston and nut, it screws into the soil chamber. it has a gasket on it, and is likely worn from the hot water and you will need to replace this part. not an expensive part. without the model number, i can't say for certain that your machine has this part. but if it does, and it is worn away, all the water will not drain from the tub. hope this helps.

Usually there is an item called a flapper inside of the drain pump that will break off and plug the drain hose. Not easy, you must remove the pump.