When you turn the thermostat up, the furnace does not immediately start. I may take several minutes for it to come up to temperature so that the fan will start. On mine, just about the time I think it is not working, the fan comes on and all is well. Make sure your propane is on and that the lines are purged of air. Does the stove light? If not, the tank could be shut off or it may be empty. If the stove lights, try the furnace several times: 1 Turn the switch to on. 2 Turn up the thermostat. 3 Wait several minutes and see what happens. If no heat, turn off the switch and let it sit for five minutes to reset itself and then go back to step 1. Follow this procedure several times. It may take several tries to purge any air in the gas line. If it tries to light and doesn't fire the internal safety controls will shut off and require you to reset. That is why you shut it off and wait five minutes. All the above assumes that you have the necessary 12 volt power available.
Good luck and keep us posted