fsd fitting?

I have bought a new FSD for my rangemaster gas oven as I was assured by the manufacturers that this is why the oven lights but will not turn up or down. It is a non patented part but apparently does the job. I am now having trouble getting the old one off. Looks like one of the threaded connections has red sealant in it. Can I use a blow torch to help unscrew this or is there some other handy hint ?