Answer Richard, You will need the machine control board WPW10174745, located on the inside of the cabinet on the left side , above the drum. " F-01 PRIMARY CONTROL FAILURE F:01 flashes when there is a primary control failure. Replace the machine control electronics." You'll need to remove power to the dryer and remove the top panel to access it. Read More... Answered by AppliancePartsPros.com | Wednesday, November 12, 2014