This is the third Travel Trailer that I have owned, and the third to have furnace problems. I have an 06 Gulfstream and just got back from a cold stay at Lake Murray in Oklahoma. The problem is that my furnace started to work, went through two cycles and now has quit. I have gas, the 12 volt battery is fully charged and the other appliances work well. I can smell gas coming from the exhaust outlet of the furnace and I think that I can hear the clicking of the electric lighter. Why is it not working. I can work on most anything, but pulling a furnace out is a task and it costs to take it into the shop. Is there an easy way to figure out the problem. It has a wall thermostat for both the heater and the a/c.