How old is my Armstrong Air unit?
Armstrong Air is part of Lennox International (Allied Air Enterprises). 3 serial formats sourced across central air conditioner, heat pump, furnace.
Serial number decoder for Armstrong Air
Type the serial from the data plate, not the model number. Nothing is sent anywhere; the tables are in this page.
Format example: 5899L17212
- Armstrong Air air conditioner serial numbers in the 1973 to present format encode the year as digits 3-4 (YY) and the month as letter at position 5 (A=Jan .. M=Dec, I skipped) (source: building-center.org).
- Example: serial 5899L17212 decodes to November 1999.
- Armstrong Air air conditioner serial numbers in the 1978 to 1992 format encode the year as char 8 via table (table below) and the month as char 7 (A=Jan .. M=Dec, I skipped) (table below) (source: building-center.org).
- Example: serial A14019ELA decodes to May 1990.
- Armstrong Air air conditioner serial numbers in the before 1972 format encode the year as digits 1-2 and the month as digit(s) 3(-4), 1-12 (source: building-center.org).
- Example: serial 6512 decodes to December 1965.
- Armstrong Air's official lookup at armstrongair.com returns warranty / registration lookup.
Decoder pages by product
Format eras
- 1978 to 1992 VERIFIED
A#####AAACentral Air Conditioner, Heat Pump, Furnace, Packaged Unit - 1973 to present VERIFIED
####A#####Central Air Conditioner, Heat Pump, Furnace, Packaged Unit - before 1972 VERIFIED
####Furnace, Central Air Conditioner
Official lookup: the authority
Open the official Armstrong Air lookup takes serial number; returns warranty / registration lookup; URL verified live
This site is a reference built from published tables. The manufacturer's own lookup wins whenever the two disagree.
What we could not confirm
- Armstrong Air is treated as sharing Lennox's format because the source lists it in that family; the corporate relationship itself is an estimate.
- Armstrong Air Conditioning Inc. is part of the Allied Air division of Lennox (building-center + site footer). Styles 4607B20058 (Lennox PPYYM) and A14019ELA / A25175KKA (1978-92 month-letter/year-letter/plant). armstrongair.com/resources/faqs/warranty/ exists. Allied serial lookup: https://apps.alliedconnect.com/WarrantyPeriodLookup/ExtendedWarrantyLookup.aspx?Alias=ALD&USERSORG=AR01
Sources
- https://www.building-center.org/lennox/
- https://www.lennox.com/residential/owners/assistance/warranty/official
- https://www.building-center.org/armstrong-air-hvac-age/
- https://www.building-center.org/wp-content/uploads/2017/09/ARMSTRONGAIR2-HVAC-Age.png
- https://www.building-center.org/armstrong-hvac-age/
- https://www.building-center.org/airease-hvac-age/
- https://www.building-center.org/wp-content/uploads/2015/09/Style-2_Airease-Date-of-Manufacture_Serial-Number-Nomenclature.png
- https://www.building-center.org/magic-pak-hvac-age/
- https://www.armstrongair.com/owners/warranty-registration/official
