We have the Kenmore Elite Dryer, Model HE3. It stopped drying over the weekend. I thought lint had collected either in the vent or the roof exit flapper vent, but neither was the case. I also checked the fuse box. I get a P4 reading (I believe) but I don't have a manual to refer to to see what this means.

Any thoughts on what could be the matter?

Thanks,

Jeff M.

First of all : you ALWAYS have to clean the air filter from lint before running any drying cycle. Lint can cause unnecessary heating up, fire, equipment failure, and it cost money for extra electricity use.
Start checking the wall socket : remove the dryer power lead, and connect something else to the socket : does that work? If so, there is power. If not check the breaker.
If the breaker is out, the dryer may be the cause. Or another appliance on the same circuit. Or operating two heavy duty appliances at the same time on the same circuit (overloading).
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With the power cable on the ground (safety first) open the dryer by removing the back cover.
Check for problems : is it possible to rotate the drum by hand? Is the driving belt broken or slipping?
Without proper equipment like a multimeter it is impossible to check if the heating element is faulty or not (that is a possibility!).
Once you have more data, please come back to me for further advice.
Success!
As always : if this solves your problem, please rate the answer provided! Feed back is always appreciated!
;)

Just because an error came up doesn't mean there's a problem,

It simply means there was a failure during the cycle,

If it returns on a regular basis, you have a problem.

Press PAUSE/CANCEL twice to clear the display.

Whirlpool Duet front load washer, HE3, HE3T, Kenmore, front load washer, door boot

This dryer was made by Whirlpool -- I did not see the P4 error code you gave

Test element and thermostats. Also check for loose connections

Dryer won't Heat!