Product review (5 stars): Easy Fix
Do not call a repairman to replace your water valve!  My washer would continue to slowly fill even after the machine was shut off.  I figured it was the valve.  I ordered the valve and received it quickly.  The repair took no more that ten minutes from start to finish and it works perfectly.  Anyone with even the most basic skills should be able to swap out the valve. The hardest part of the job was moving the washer away from the wall and disconnecting the supply hoses.