Well, this is a new one on me and doesn’t match anything that I have in all my research, so let’s see if someone else has something.
Fraser & Johnston
Model number 80HD36ANA
Serial Number C148850
BTU - 80,000
House was built in 1960.
Current owners have been there since 1979.
I’m familiar with F&J, so the serial number had me puzzled at the time of the inspection, but it was quite clear, and the number 1 would not be the letter I since F&J didn’t use the letter I.
My guess is 1979-1980 since all the other appliances were 1979-1980, or 1993 since the roof was put on in 1993.
Russel, my Preston’s CD lists that model number as being current for 1973-74, but also the HD series in general was produced upto 1977 (no idea why it isn’t in the paper version of Prestons, but have had that problem before).
Usually that C in the serial number would be 1973 or 1993, but that’s when there are two, three, or four letters as the first digits in the serial number. I’ve never run into a one-letter serial number before.
Based on your information, looks like I’m going to go with 1973.