Rob,
That mite be an option
My ac is also a armstrong unit and from what I gather these were real top of the line. How can I test if there is feron in it? I think thats out of my league for Fixen, I have the manuals for the unit but it dosn't tell you any easy thing to look for. I just hate to bring it to a trailer place and have them just say you need a new one without even looking at it!
Thanks, Frank