I had a space heater (Hot wire, ceramic and oil don't matter for this post) T-Stat fail due to a power surge.. I got a plug in "In-line" 125 volt T-Stat for about 30 bucks (Since I really liked that heater) and used it till the heater finally bit the final dust.
This unit consists of a plug/outlet body (15 amp) a cord and a box which is the actual T-Stat
I also got a 2nd one (Same source) that's mounted on the outside of a heater that had no T-Stat, Works better, and I mean FAR better than any built in T-Stat I've ever seen.. It is on the air-intake side of the heater (Cool side) so positioned that it is NOT warmed by the heater itself. (Both of them are so positioned) only by the air in the room.. Nice big way overkill rated Micro-Switch comes out the back of the thing.. Works great.