Furnace age question...Power of the web

I just received a call from someone looking for help. Here is his request:

Greg try this. Might help with the age at least.

Nevermind Greg, can’t get an attachment in to save my life. I’ll just call you.


Yeah, I looked at this again, and my initial guess was way off, but you should be able to find it through that code in the file.


A letter followed by a 9-digit number. The second and third letter represent the year, the fourth and fifth numbers represent the week. There may be a date stamp to the right of the serial number.


Serial Number: R883512345 Date of Mfg: 09/88

So in my case, the furnace would have been manufactured in 1961?
“Serial# - H61139301”

Nope, I think the first two characters are used. It’s a 1986, H for the 1980’s and the 6 is the year. H6 = 1986.