quick question before you go down the road of replacing the t-stat.
If you turn it on and the burners light and then it kicks off. The next time it comes on do the burners light or if you raise the temp will it light without having to turn it off and back on?
I want to make sure the switch on your induction fan isn't the culprit. If that switch doesn't sense enough air draw it will shut the furnace down and put it into safety lock out which means you have to turn it off and back on to get it to light again. That was why I asked earlier about shore/battery power. I had a camper once that the heater would run fine on shore but gave me problems on battery. It was because the fan didn't spin fast enough to close that switch.
