I'm not familiar with the thermostat you have, it may be the problem, or it may be a 'smart' thermostat that detects other issues. There are several other possibilities that may shut the furnace off. First is the propane leak detector, should be inside the trailer near the floor, since propane is heavier than air. An intermittent electrical connection to this detector will cause it to shut off the propane supply and no propane appliance will work. Another possibility is the 'sail switch' in the furnace air intake, if air flow drops too low, it will shut off the furnace only. Intermittent or low voltage to the furnace blower or even a defect in the blower may cause a temporary drop in air flow and the sail switch will shut the furnace off. Finally, propane pressure may be marginal caused by a pinched line or regulator set too low and then the water heater or stove turning on may drop the pressure too low for the furnace.
Texas Baptist Men-Retiree Builders member since '01
13 Silverado 3500HD D/A, 2wd CCSB srw, custom RKI bed
11 Cruiser CF32MK