Tom and Ron,
I have used it on DC only when the unit switched over during the time when we were having problems keeping the LP lit. We did have to replace the piezo.
Ron, your dealer tried to talk me out of it as well, but I went ahead and bought it as a backup.
Forgetting that I did order it as an extra, my wife just reminded about that .
Beyond the ignitor, the fridge has done the job.
Bill