# Need Armstrong furnace age **URL:** \ **Category:** Inspecting HVAC Systems\ **Created:** [November 21, 2012, 5:11pm UTC](https://forum.nachi.org/t/need-armstrong-furnace-age/73600 "2012-11-21T17:11:55Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![nsusdorf](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/nsusdorf/32/1839_2.png) [@nsusdorf](https://forum.nachi.org/u/nsusdorf)\ **Post date:** [November 21, 2012, 5:11pm UTC](https://forum.nachi.org/t/need-armstrong-furnace-age/73600/1 "2012-11-21T17:11:55Z")
Armstrong Model number: G7A100DC12-11 Serial: A25175KKA House was built in late 50s. The only number I see in the SN is 75, but it didn’t look that old. Thanks for the help!:mrgreen: ![DSCF8003.jpg](https://global.discourse-cdn.com/internachi/original/2X/0/04509c89383539829285748116fcac470d73d24b.jpeg) ---
**Author:** ![lkage](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/lkage/32/347658_2.png) [@lkage](https://forum.nachi.org/u/lkage)\ **Post date:** [November 21, 2012, 5:35pm UTC](https://forum.nachi.org/t/need-armstrong-furnace-age/73600/2 "2012-11-21T17:35:46Z")
I believe the second K is 1989…and the manufacture age is, typically, within 2 to 3 years of the ANSI date. Use the search function above for further info… ---
**Author:** ![nsusdorf](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/nsusdorf/32/1839_2.png) [@nsusdorf](https://forum.nachi.org/u/nsusdorf)\ **Post date:** [November 21, 2012, 5:37pm UTC](https://forum.nachi.org/t/need-armstrong-furnace-age/73600/3 "2012-11-21T17:37:34Z")
Thanks! ---
**Author:** ![cbottger](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/cbottger/32/206_2.png) [@cbottger](https://forum.nachi.org/u/cbottger)\ **Post date:** [November 21, 2012, 7:06pm UTC](https://forum.nachi.org/t/need-armstrong-furnace-age/73600/4 "2012-11-21T19:06:57Z")
According to my reference the first K is the month (oct) and the 5 before the K would be 05-95-85-75 take your pick ---
**Author:** ![mgratton](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mgratton/32/58251_2.png) [@mgratton](https://forum.nachi.org/u/mgratton)\ **Post date:** [November 21, 2012, 7:50pm UTC](https://forum.nachi.org/t/need-armstrong-furnace-age/73600/5 "2012-11-21T19:50:29Z")
1989 ![Scan 1.jpg](https://global.discourse-cdn.com/internachi/original/3X/9/2/922cbab3c77935deb9c5782d6eb844fe04483247.jpeg) ---
**Author:** ![lkage](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/lkage/32/347658_2.png) [@lkage](https://forum.nachi.org/u/lkage)\ **Post date:** [November 21, 2012, 8:37pm UTC](https://forum.nachi.org/t/need-armstrong-furnace-age/73600/6 "2012-11-21T20:37:32Z")
> [@mgratton](#): > > 1989 [http://www.nachi.org/forum/attachments/f20/60412d1353527695-need-armstrong-furnace-age-scan-1.jpg](http://www.nachi.org/forum/attachments/f20/60412d1353527695-need-armstrong-furnace-age-scan-1.jpg) Thanks, Marcel. ---
**Author:** ![lkage](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/lkage/32/347658_2.png) [@lkage](https://forum.nachi.org/u/lkage)\ **Post date:** [November 21, 2012, 8:38pm UTC](https://forum.nachi.org/t/need-armstrong-furnace-age/73600/7 "2012-11-21T20:38:10Z")
> [@cbottger](#): > > According to my reference the first K is the month (oct) and the 5 before the K would be 05-95-85-75 take your pick What reference are you using Charley? ---
**Author:** ![cbottger](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/cbottger/32/206_2.png) [@cbottger](https://forum.nachi.org/u/cbottger)\ **Post date:** [November 21, 2012, 10:59pm UTC](https://forum.nachi.org/t/need-armstrong-furnace-age/73600/8 "2012-11-21T22:59:35Z")
> [@lkage](#): > > What reference are you using Charley? [http://www.buildingcenter.org/content/hvac-production-dateage](http://www.buildingcenter.org/content/hvac-production-dateage) I was looking at this one and it was not real clear on Armstrong ---
**Author:** ![dwilcox5](https://avatars.discourse-cdn.com/v4/letter/d/65b543/32.png) [@dwilcox5](https://forum.nachi.org/u/dwilcox5)\ **Post date:** [July 21, 2020, 3:08pm UTC](https://forum.nachi.org/t/need-armstrong-furnace-age/73600/9 "2020-07-21T15:08:35Z")
I have what appears to be an older model Armstrong and there is no sense of sending a photo because it is so deteriorated that I have to move the name plate around in the sun just to read it… Mod # SA36SA-1 (assuming 3 ton) Ser # 22667EMA (assuming 1967?) Thoughts? ---
**Author:** ![jdepiero](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jdepiero/32/356888_2.png) [@jdepiero](https://forum.nachi.org/u/jdepiero)\ **Post date:** [July 21, 2020, 5:16pm UTC](https://forum.nachi.org/t/need-armstrong-furnace-age/73600/10 "2020-07-21T17:16:26Z")
In that style of serial number the E=May and the M=1991