DI have dealt with 4 Dometics that has had this issue at altitude (about 7K to over 10K) every one works at high altitude now. The fix was simple. High altitude and cold are the biggest issues. Lack of oxygen due to high altitude means the unit is running lean. At night once the unit shuts down the property of propane changes. At this point the flue is cold and does not draft well. The lean flame "lifts off" the burner due to the lack of draft and the flame looking for O2 as the flue warms more air is being drawn in. The Dometics we have use the Igniter as the thermocouple . When the flame lifts there is no longer a path to ground. The unit shuts down. The igniter is 1/2 of the cycle and it then watches for ground the other 1/2. Tried lots of things but the simplest thing was to move the igniter in and up. This is so when the flame lifts the igniter "sees" ground
