I’m inspecting my way through some apartments built in the 1970’s, and the furnaces are all Westinghouse. Serial numbers are all in this series: Q27291, Q27292, etc. From their appearance I would say the furnaces are 1970’s also, but I’d like to be more specific. How can I find out their ages?
The cheat sheet I’m using for HVAC is one I obtained on this message board a while back. It doesn’t include Westinghouse, and every once in a while I come across another manufacturer that’s not included. Any leads on finding a list of serial number/age codes that is pretty complete?