Thank you for submitting a question to Manage My Life.
Without your model number I am only able to give you general information.
The PF indicates a POWER FAILURE. "PF" flashes to indicate that a power failure occurred while the dryer was running. Press START to continue the cycle, or press PAUSE/CANCEL to clear the display. Any electrical interruption to the machine such as a circuit breaker being reset or weather related power outage can cause a PF error code. Try resetting the appliance by disconnecting it from the outlet or switching off the circuit breaker for 20-30 minutes, and then restore the power. If the reset doesn't work, I strongly suggest scheduling service.
This typically occurs when there is a loose wire in the terminal block or outlet. The diagnosis of this issue will require the use of an ohm/volt meter and you will have to perform ohm checks and/or live voltage checks. If you have an ohm/volt meter and are confident in your technical abilities, please reply below and I will be happy to assist you further.
If you do not feel confident repairing this problem yourself, then you can have it repaired at your home by a Sears technician. Here is a link for the website:
Sears Home Services
Here is a link that you may use to view the parts list diagram or for parts purchases;
Sears Parts Direct
If you would like specific help with your dryer, please reply to this post with the model number and more details.