Question about propane tanks

I vote for a fill/emptying issue. If the OP had taht much of a leak, it would surely smell. I agree to weigh both tanks empty and full to see how much is used. My guess is that it's a plumbing issue internally in the tank.

I'd bet leak. But why guess? Go to a real propane shop. Not a gas station, but a propane distribution center. They'll test the tank for you. And fix it if possible. Cheap, easy, and no guessing.

You have a leak.

When you have your cylinders refilled (tanks are in MHs) do they both take at least 7 gallons?

When refilling your cylinders is the place that refills using a scale? (BEST Method ----most accurate)
By opening the 'bleeder' valve? (Second best.....liquid spews when cylinder is filled)
By waiting until OPD shut-off filling? (Least desirable method due reliance on a float)
By measured gallon? (Worst method cause it is not temp compensated)


Relief valve on cylinder could be weeping
OPD threads could be leaking
OPD bleeder valve could be leaking

Crimped connection on pigtail hose could be leaking

A little time/effort checking for leaks using soapy water could find the culprit
(Rinse soapy residue off thoroughly after checking)

Some P/P tanks will not fill all the way. you think they are full, they ain't.

try weighing them when full, and empty, because some will not deliver all gas in the tank.

I had a similar problem on my last camper. I tried switching positions of the tanks a few times just to rule out any leaks with any of the hardware in the camper.

When the same tank went faster, no matter which side it was on, I was pretty certain the problem was in the tank and not the regulator or trailer plumbing. I never smelled gas.

As a final test I left the questionable tank on over the winter. Tank was full. Other tank shut off. When spring rolled around, yup! Tank empty. I purchased a new tank.

Are these fairly new tanks? Are they both being filled to 7 gallons? Then you probably have the selector valve set to both.
Set to left or right and switch after several days.

check for leaks?