I took the decoder posted on this site, found a couple more online, added some from my own experiences over time, compared them all, combined them and put together in this much shorter version that only focuses on year of manufacture. It's not near as detailed but its less for me to carry around. Im sure that it's not perfect , as its a work in progress (I have not run into all of these manufactures). If anyone has any additions, or sees anything incorrect let me know. I Just thought that some of you guys may be interested. Download Attachment: Furnace Age Chart.doc 53.16 KB
