HVAC Age Help

Century furnace manufactured for heat controller for?
The ANS tag in the lower left corner is Z31.47 1978

If I use century or heat controller it says 45 week of 2006. This is a larger unit with a separate air box on the back of the unit. It looks like its from 1980 to me.
Any help would be appreciated.


From Furnace age help - InterNACHI Inspection Forum http://www.nachi.org/forum/f79/furnace-age-help-98904/#ixzz3StpG8fv4

In the serial #. The date code starts after that first sting of 5 characters.

Manufacture- Heat controller
F4980 (week then year)
Date manufactured - 1980 week 49