The dishwasher operates well, but after it is finished the cycle, the bottom will fill up with water. I can drain it by pushing the cancel button, but it just fills up again later in the day.
Here are your parts.
Parts for Whirlpool KUD121SS1 Dishwasher - AppliancePartsPros.com
Does water leak into it slowly?
Is the water leaking in clean and hot?
If yes then it could be that your fill valve is leaking.
Has this unit ever workrd OK in the same location with the same plumbing hook up?
If not then it could be that there is a problem with the drain system and water from the sink/garburator is siphoning back into the unit.