I have a Kenmore 110 electric dryer that runs but doesn't heat on any cycle or temperature setting. I have checked the breaker, voltage, heating element, thermal cutoff and thermistor. I have bypassed heat relay and ran diagostics. All checked out. I figured it must be the control panel so I replaced it and it heated for about 2 minutes and now it doesn't heat at all again. Everything works except there is no heat. Not sure how to check centrifugal switch or if that could even be the problem. Please help.

It sounds like you have a grounded hot wire or a short somewhere. The only way to find it is to start at the plug and work your way through the wiring in the dryer until you find it. Here are some manuals: https://dl.dropboxusercontent.com/u/8010163/Whirlpool%20Dryers.zip