[77newell]

I agree with Sean's note just above based upon my experience with Suburbans. Regarding the thermostat if it is like mine you can hear it "bing" when the temperature in the coach reaches the set point. If you hear the "bing" then it should the furnace should kick in, with one possible exception that I've experienced. Once you hear the "bing" and the furnace doesn't kick in try Sean's suggestion of jumpering the points in the thermostat. If that causes the furnace to kick on then I would suggest trying to lightly file the points in the thermostat. That worked on one my my thermostats. The other thing to try prior to pulling the furnace apart and taking the circuit board out to be checked is to pull the thermostat wire connections on and off the board a couple times to scrub off any potential corrosion that could be preventing sufficient current flow when the furnace heats up, this was a problem once for me.

Please let us know what you find ultimately is the problem as this helps us all learn.