Dishwashers

The dishwasher does not completely drain at the end of the cycle.

Dishwashers are supposed to leave some water in the unit at the end of each cycle in order to keep the heating element (for drying the dishes) from burning up. It's similar to a water heater element.

Chances are that the drain is clogged if a lot of water stays in the bottom.

A partially clogged air gap will do the same thing. The air gap is the small chrome piece that sticks out above the sink on the kitchen counter.