For example, split serial number 8498C13579 as 84 | 98 | C | 13579. The code 84 identifies Armstrong, 98 means 1998, C means March, and 13579 identifies the individual unit. The plant code and unit sequence do not influence the manufacture date.
Armstrong Air month letters run from A through M and skip I. The serial number alone is enough for Appliage to return the manufacture month and an estimated age, so the model number is not needed.
Appliage decodes Armstrong Air dates from one set of positions. Digits 3 and 4 are the year and position 5 is the month letter, so 8498C13579 is March 1998. The documented Allied Air format starts in 1993. Year codes before 93 in the previous century do not produce an Armstrong Air date from this layout. The tables are under Armstrong Air Serial Number Decode below.
Find the Age of Your Armstrong Air HVAC Unit with Appliage
Enter every character from the Armstrong Air serial number. You can leave the model number field blank because the model number does not change the age result for this structure.
A valid two digit year from 1993 onward and a month letter from A through M, excluding I, produce one estimated manufacture month. Year codes that would point to a date before the documented 1993 start do not produce a date from this layout.
Armstrong Air Serial Number Decode
Plant Code
| Plant code | Brand or production group | Effect on manufacture date |
|---|---|---|
| 84 | Armstrong Air | Identifies the Armstrong production group; the year and month come from positions 3–5 |
Month Codes in Position 5
| Month code | Manufacture month |
|---|---|
| A | January |
| B | February |
| C | March |
| D | April |
| E | May |
| F | June |
| G | July |
| H | August |
| J | September |
| K | October |
| L | November |
| M | December |
Armstrong Air skips the letter I. If position 5 clearly contains I, the serial number does not match this month table.
Armstrong Air Year Codes in Positions 3–4
| Year code | Manufacture year | Example |
|---|---|---|
| 93–99 | 1993–1999 | 98 means 1998 |
| 00–26 | 2000–2026 | 07 means 2007 |
| 80–92 | No date | The published Allied Air format starts in 1993; these codes would mean years before 1993 and are not dated from this layout |
| 27–79 | No current result | The 1900s year is before the published 1993 start, while the 2000s year is still in the future |
The Lennox and Allied Air nomenclature uses the same plant, year, and month positions across this production family. The published Allied Air format starts in 1993; older serials need a different, documented format before they can be dated.
Armstrong Air Serial Numbers Appliage Cannot Find the Age
Appliage uses the Allied Air format of plant, year and month for Armstrong Air equipment from 1993 onward. A shorter serial number, a serial with nondigit year positions, or a month letter outside A–H and J–M does not match this rule, and Appliage returns no manufacture date for it. Year codes that would point to a date before the documented 1993 start do not produce a date from this layout.
An unlisted plant code may still have valid year and month positions, but code 84 is the code that identifies Armstrong Air in the published table. If the brand or plant characters are unclear, use the complete rating plate before accepting the date.
The serial number gives the month the unit was built. Installation invoices, permits, and warranty records provide later dates and answer different questions.
Armstrong Air and the Allied Air Family
Allied Air publishes one serial number table for several HVAC brands. Armstrong Air equipment in this group uses plant code 84. Other plant codes may identify Lennox, AirEase, Concord, or another related production group.
The Lennox serial number lookup lists the other plant codes that use the same order of plant, year and month.
Sources
- Allied Air serial number reference. The reference explains the factory, year and month positions. It identifies 84 as Armstrong. Archived copy.
- Lennox serial number reference (archived). The Lennox examples use the same date positions.
- Armstrong Air official website
- Armstrong Air warranty registration
For other brands, see our appliance serial number lookup.
