Bruce,
Don't hesitate to call Peter at Air Force One. About six weeks ago he called me and said he was sending me a new, updated tank assembly because of some problems that became apparent after all the units he sold and installed at Sevierville. I did receive the replacement and went to his recommended dealer about an hour from me and had it installed.
I did not have any problems with the first tank assembly but he wanted to replace it anyway. He needs to be made aware of your problem since this was the second time (I think) for you.