My dryer won’t stop running if the door is shut. It isn’t heating up, just running. If I try to run a cycle, I get a "pf" power failure notice. I have flipped the breaker to reset, but it is still running.
It may be a failure of the Electronic Control Board. Here is the part you need.
http://www.appliancepartspros.com/whirlpool-power-cube-asm-wp3407228-ap6008588.html