Check your LEAK DETECTOR RE-SET SWITCH, it should be located inside the motorhome. Just last week I wanted to run my (2) furnaces before winter to make sure they were in good order, and neither would lite. I could hear the fuel valve activating but no flame. I then checked the stove for possible air lock, and it would not lite. As the last resort, the water heater would not lite either, telling me there was no gas flow. I then re-set the detector swith and WALLA, everything is normal. Ours is located close to the floor in the kitchen area, just a good safety item. Good luck, Happy trails & travel safe.