You sure the tank is empty? - Propane liquefies at -42.1° and i have heart from colleagues who lived in Fairbanks Alaska that their propane tanks frequently froze during the coldest winters. I was told it is a double-whammy, first it is cold outside and then in order for the propane to turn from a compressed liquid into a gas the liquid cools down even further until not enough to run the furnace can be gasified…Good morning the the frozen north. Ran out of propane on the coldest night of the season so far. Of course.