Refrigerators on BC Ferries
Refrigerators on BC Ferries, and other places I would imagine, must have the propane turned off for safety reasons. A trick I learned, to prevent an air lock in the propane line, is to turn off the refrigerator from the inside of the trailer then turn off the propane. If just the propane is turned off then the refrigerator still has access to the propane in the hose until it is used up and that used to cause an airlock and difficulty relighting.
works for me!