It is 15 degrees and I tried to turn on my propane as I wanted to do some work on the inside of the camper and the propane will not work on either tank. Could the regulator be frozen?
Yes, they do freeze. The forum gets several posts like this every winter. You can put a small light bulb next to it in order to thaw it or you might just replace it and hope that perhaps a build up of excess moisture was in it.