Every effort is undertaken to offer you correct and concise information to assist you in determining the age or manufacture date of HVAC equipment. Anytime anyone is dealing with numbers and letters in determining data, mistakes and misinterpretation are bound to happen. For this reason if you find during your research that we may have erred please contact us. In addition perhaps you have come across a brand, model or serial number format that we have not addressed. Email us information or pictures of data/nomenclature plates of the unit and we will attempt to assist you in your determinations. Email
This page was last updated: 25 July 2009
General Electric
Serial Number format: 580439 947
(This serial number was transcribed from an actual unit during a home inspection).
Using the seventh, eighth and ninth digits (or last three digits) of the serial number 580439 947 you will find the year and week of manufacture. The seventh digit is the last number of the year and final two digits (eighth and ninth) are the week. The GE age determination system is weak and other clues as to the age may be needed (i.e. furnace condition, maintenance schedule, owner’s manual, etc.). The GE age determination system is weak and other clues as to age may be needed (i.e. furnace condition, maintenance schedule, owner’s manual, etc.). This unit was manufactured the 47th week of either 1979, 89, 99 or 09.
Year of manufacture: 580439 947
Week of manufacture: 580439 947