serial/age of Westinghouse furnace, & newer cheat sheet

David P. Valley, you are correct. Nordyne bought the NAME. As for the post of Westinghouse made A/C just in the 70’s, thats not so. My father-in-law installed and worked on Westinghouse products in the 30’s. I have worked on systems he installed in the 1950’s plus those that others installed. I knew the date codes then(I have forgotten due to lack of use) and they depened on the first two letters of the serial number. I’ve been in the HVAC business since 1968 and it is now 2012. Wow, I guess that makes me OLD.