Like most stovetops, what my gas stovetop says is "low" heat is hot enough to boil a pot of soup or braise. I have often resorted to using a heat diffuser to tame it down to a simmer. My mother in law just shared a little trick with me that maybe you already know, but was new to me. Instead of turning the dial down to "low," get it lighted but then turn the dial to the left like you are shutting it off, you can get a MUCH lower flame this way. I was hesitant at first thinking the flame might blow out, but after a couple months I haven't had any issues.