If that doesn't fix it up, then it may be one of the element wires having trouble making contact or partially coming apart and causing the super heating issue.
This was my problem. I would turn the seat on, even on low, and it would get so freaking hot I couldn't stand it. But only in one spot I noticed eventually. So I pulled the seat cushion off and found there were two wires touching and shorting causing it to heat more than it is supposed to. You may need to replace the seat cushion.