Re: Propane heater wont ignite
The furnace runs off the battery, and if your battery is low, you might get the fan to come on, but the furnace will not ignite (have to have the battery power for the fan to run at a certain speed for the sail switch to open).
Once when I had this problem, it was due to me not 'turning on' the switch on the thermostat - mine has an on/off switch (rather stiff) on top, and the bottom switch is the temperature setting. Mine is located less than a foot off the floor, and required me and the flashlight to sit on the floor to explore the setup.
The other possibility is the 'reset' switch which is located behind the cover of your furnace. You might remove the cover, and try resetting the furnace, and maybe (if battery is charged) you will get the fan, then a clicking noise and finally ignition!
Best wishes.