Lennox furnace age

Today’s inspection. Home built in 1935. This furnace had virtually no info on the plate. Only info is: Lennox “Aire Flo”, “Type 514”, “No. 3”, “Style 21”.
Any help on the age of this unit would be greatly appreciated!

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I have called them before, very helpful people if you have enough info for them to help. 1-800-9-Lennox](http://www.lennox.com/business/callcenter.asp)

Jeff,

When I run into a furnace that age and the date can’t be deciphered, I note any defects and insert the following statement…

*The heating system was paced through it’s normal sequence of operating modes, with no obvious defects noted at time of inspection. However, due to systems age, it is clearly beyond it’s life expectancy, and replacement should be considered. Until then, I recommend annual maintenance from a licensed contractor. *

Thanks guys!

Some of my research indicates that prior to 1972, the type was the manufacture date, so I would guess April 1951.