Kenmore 80 series dyer will not heat up to dry the clothes in the dyer, but it will start.

I would check the thermal fuse. Here is a link (https://www.askmehelpdesk.com/appliances/kenmore-dryer-not-starting-209359.html#post1011867) that may prove useful.

If not the fuse, then the element itself may be burned out. This can also be easily checked with a ohmmeter. Or visually sometimes.

Best of Luck,
WallyH