I have a Jotul gas stove hooked up to propane. Problem is the spill switch keeps opening, shutting everything down. I have it vented with a 5 inch rigid liner to the roof through the chimney, Sometimes the stove will run for hours, but most times shuts down within 20 minutes or less, 5 or so if lucky. Tried many venting things, this is a single story building, with the spill switch pulled out of the chimney it seems to work fine. Replaced switch thinking it may be bad but new one made no difference. Since we got this used is there a possibility that it was set up for natural gas instead of propane, would that cause the issue? Since the vent line was recently replaced it isn't blocked and you can feel heat rising out of the chimney, I have no idea. Any suggestions, we have the flame set to low. How hot does the spill switch need to get to open up?