I purchased this 5 burner cooktop used and discovered it has a check date of 6/23/00 -much older than it appeared. All the burners light and adjust thru to low, but NONE of the extra low stay lighted when I turn them to the superlow setting..they click and I can hear the gas valve turn off. It relights fine when I dial it back to low setting, and I hear the valve turn back on at the burner. I am kind of lost here, as I can't seem to get a manual and my experience with cooktops was replacing the valves in a much older unit years ago. (and I got them all in the wrong burners, then!)

This unit was purchased from the fundraising location of Habitat for Humanity, and I was told it was set for LP gas. Not even sure if that was true...but no idea how to tell! Would the unit work at all if it were set up for Natural Gas and I connected it to LP?

I know, a lot of questions here! I really need some help..I am pretty handy with most things, just don't quite understand cooktops.(yet)

;)Thank you VERY much for suggesting that these burners work by turning the gas valve on and off to maintain the temp! You were 100% correct-I suppose this was something that was in the manual, which, in keeping with my experiences with Thermador (this is my 3rd cooktop of theirs in the last 30 years) is NEVER available once they discontinue a model. It's like they don't want people to have them. Sheesh. Thanks again!:) -Tuolumne Nick