Anyone had any trouble with this type of iron overheating the iron making it glow red. I think the trouble is in the pot for adjusting the temp. The last time I used it, it seemed to be off on temp from what I normally use. When I turned it on to use it this time it got so hot, the tip was glowing red. I pulled the cover off but wasn't sure how to get pin connector out for iron connection. Anyone messed with these things or do you just trash it and buy another?