My Kenmore elite HE4 electric dryer will not work. The screen displays "PF" power failure, but there was no power failure. Th dryer is maybe 2 years old and worked fine until now. I tried holding down the START button but it still doesn't work. I tried unplugging and tripping the breaker still nothing. The end cycle light beeps constantly and unless I hold down a button it keeps beeping. What can I do to fix this?

Unplug for about 15 minutes. Than plug in again : does the same problem appear again?

:)

I know this is an old question but the same thing just happened to me. I paid someone to tell me this. Unplug it, plug it back in. If the error code is "PF" hit cancel and then it should work again.

Thanks for posting this guys!

Check breaker first. Unplug for 15 minutes. Plug back in. Hit cancel and it should work. Mine did!

Purchased as kenmore elite secondhand front panel has power but it won't start hold down start button for the 15sec.. hear a beep and a click time starts counting down but no heat or cycle what could be the problem

Most likely it is dirty and lint deposits have built up, as it always does, in all the air ducts which will cause the sensor to give an error code. You will have to take it all apart and clean the drier out thoroughly or it is all for nothing. Every air duct will have to be removed and scraped and washed out to remove baked on lint deposits which bakes on like a concrete lining. This will burn so the manufacturer has installed the sensors to keep from having a house fire. Driers were the number one cause of fires at one time, hence now we have safety sensors. Look at: How to clean your clothes dryer. How to make it hot again. - YouTube (http://www.youtube.com/watch?v=MMP7BW1lLs4) to see how. Also look at these to get an idea about how to clean it: Mr. Appliance Tips: How to Clean Your Dryer - YouTube (http://www.youtube.com/watch?v=iBiRw-KElC4) ; Cleaning a Dryer Vent and Lint Trap - YouTube (http://www.youtube.com/watch?v=yFTZGgVisCI)
Electric Clothes Dryers (http://www.electrical-forensics.com/Dryer/ElectricClothesDryers.html) Dryer vent cleaning prevents fires - YouTube (http://www.youtube.com/watch?v=A6wmD502-xE) and: Cleaning out a dryer with top lint cleanout - YouTube (http://www.youtube.com/watch?v=OBNDbyRm68M&feature=fvsr)
Cleaning out a dryer: By a woman 2 of 2 - YouTube (http://www.youtube.com/watch?v=a73HTFkcB90&feature=relmfu)
Whirlpool Dryer Model LE5800XSW3 Wiring Diagram | Dryer Repair | Fixitnow.com Samurai Appliance Repair Man (http://fixitnow.com/wp/2010/10/09/whirlpool-dryer-model-le5800xsw3-wiring-diagram/)
When you finish cleaning the drier it is best to also replace the belt, too, because you do not want to have to disassemble it all over again and if the belt is over two years old you should replace it.

Note that on most of the videos it does not show them washing out the parts, but this is important because it's the only way to really get the parts clean, just don't get motor wet or the capacitor if it has one. Vacuum out the motor to remove all dust. I would move the drier out to your garage to have plenty of space to work. You also want to check your vent and clean it, also. The vent should have a short run and be straight as possible. The job is really easier than it sounds. There is no shortcut that will work; it has to be cleaned well. Before you re-assemble it make sure to use white lithium grease (high-temp grease) and grease all bearings. Just vacuuming out the dryer a little does little good. Here are some manuals: https://dl.dropbox.com/u/8010163/Kenmore%20Dryer%20Manuals.zip