I started to post earlier and didn't. Here I go...
I assume the dial/knob will go higher?
I assume it used to work?
I assume you haven't serviced the LPG system in any way?
So to me that means you aren't getting enough pressure. I.E. bad regulator or trash in system. Might turn off both bottles and purge lp gas as lit burner. Then slowly open tank valve again. Prolly won't fix, but it's an easy cheap fix.
Then I would go to or call your local LP service company and talk to them about checking or repair.
I guess it could be the thermostat or gas valve too. I assume if the gas valve works its good.
2017 Puma 297RLSS
2005 Ram 2500 4X4 diesel SMOKER!!
I love puns, irony and tasteless jokes...
born in Texas.... live in Arkansas