Several possibilities can prevent a Whirlpool washing machine from draining properly, and one of the most common is an incorrectly installed hose. Siphoning can occur if the hose is too far down in the standpipe. Also check to make sure the hose is not kinked.
Other possibilities include a clogged drain, a bad pump or a hose clogged with a small piece of clothing preventing water from draining out of the machine. Also, a defective door switch may turn off the machine before the water has a chance to drain, or the drive belt could be slipping and preventing the wash tub from emptying.