Propane Leaking or Regulator Problem?

[Montana_469]

Our 2004 Mountaineer 318 BHS has a problem. On a recent trip with temps in the 30's, we went through 3 tanks of propane in a 4 day stay. This is ridiculous to me, we are used to going at least a season on 2 tanks. My dealer is telling me that I should open both propane valves when camping because of something to do with the long lines in the Montana's and the Marshall regulators. They say the regulator will only draw off one tank at a time, and will automatically switch to the other tank. Also say the little red cap will stay popped up to show me one tank is empty.

I am having a very difficult time in believing my not opening both tanks is causing this camper to go through propane at this rate. Anybody else had problems like this?

Thanks,
G20

2000 F-250 4x4 Diesel
2004 Mountaineer 318 BHS