age help please

Armstrong oil fired furnace
Model # L78B4DC12-1
SER# A 26682BNA


Steve are you sure this is the complete model number?

Model # L78B4DC12-1

Preston guide has a model number L78B84DC12 in 1992 through 1995.

Hope this helps.

Yes, that helps. I guess it would help to put all tne numbers in L78B84DC12-1
Steve McIntire

The last three letters of the serial number give you the date of manufacture:

B = month
N = year
A = place of manufacture

B = February
N = 1992

Thanks for the help