Arnold A Millstone Township , NJ July 10, 2016 Appliance: Whirlpool Undercounter Dishwasher DU915PWPS0 Whirlpool Dishwasher Du915pwps0: Dishwasher wouldn't drain. How to replace Check Valve Assembly. Replaced the check valve. Works fine now. Do-It-Yourself Rating: Repair Time Estimate: 15-30 minutes