If you haven't corrected the problem. Disconnect the smoke alarm and set it outside while you run the heater for about 15 minutes. That will give time for the oil that is on some new part and accumulated dust to burn off. Open up the windows
and the door. Keep an eye on it If you see a problem turn off the propane
and the unit will shut down. This is common with new units and with some that have set unused for several months. Everytime I installed a new residential unit, summer or winter, I would run the furnace
for a 15 minutes to keep from having a call back.
Another thing to keep from having a frozen blower motor or gas valve run your furnace
through a cycle every couple of months. This applies more important units get a little older.