Reflection 27RL 5th Wheel-Furnace will not stay lit. Atwood 35K BTU Furnace.

Since I purchased this unit the Furnace has not cycled as one would expect. As a Electrician by Trade, one would expect that the furnace would stay lit when the thermostat calls for heat, and the safety functions of the furnace are met.
When the furnace calls for heat the Gas Lights, a few seconds later shuts off. All the time the fan continues uninterrupted. This will continue to cycle, the gas will stay on for longer intervals. It takes a hour to heat up the unit 5 to 10 degrees.

I took the RV to the Dealer. His inspection was that the sail switch and all functions of the furnace were functioning ok.

When the season is colder, it can take 1 hour 15 minutes to heat the RV up enough to turn of the furnace, say from 55 to 65 degrees.