Contents Article originally appeared High-efficiency residential gas furnaces Conditioning ducts? • Hvac residential air conditioning Mar 11, 2014  · S/N and actual age of Janitrol Furnace do not match I inspected a Janitrol furnace that was clearly installed November 27, 1985 however, the S/N: 300406 does not tell me this (as I understand the Janitrol/Goodman dating … Continue reading Janitrol Furnace Age