What Kevin23 says. I have small shack I pull around as a portable that has a Big Buddy heater connected to a 20# tank. A couple of weeks ago I shut the heater off, but left the gas valve on when I came in for lunch, when I went back out I could smell propane and heard a hissing sound, the line had sprung a substantial leak. Moral of the story is that from now on I would be smart to also shut the tank off (even for a short period of time) and leave as much hose outside the shack as possible, having it inside leaves more risk of bad consequences. I have since replaced the Buddy heater hose with a better braided one.