Armstrong AirAllied Air Enterprises / Lennox International
Armstrong Air HVAC Age Lookup
Find the manufacture year of any Armstrong Air AC, heat pump, or furnace from the serial number.
Air ConditionerHeat PumpFurnaceAir Handler
Enter Serial Number
How to decode the serial number
Armstrong Air is manufactured by Allied Air Enterprises, a Lennox International subsidiary. Armstrong Air, ADP, Concord, and Ducane are all Allied brands using the same serial format as Lennox.
1993 to Present
Same as Lennox — first two digits year, next two week.
2317A12345
Position
Meaning
Example
1–2
Year — 2023
23
3–4
Week — Week 17
17
5+
Sequence — Ignore
A12345
Where to find the serial number
Data plate on side panel of outdoor unit or inside furnace cabinet door.
Allied Air brands use the Lennox-style year-week format.
Decoded examples
2317A12345
→ Week 17, 2023
23 = 2023, 17 = week 17
1440B67890
→ Week 40, 2014
14 = 2014, 40 = week 40
Life expectancy
Expected lifespan: 15–18 years.
Common questions
Armstrong Air is made by Allied Air Enterprises, a subsidiary of Lennox International. Allied also makes ADP, Concord, and Ducane equipment — all at the same facility with the same components.
Same format as Lennox — first two digits are the year, next two are the week. Example: 1834 = week 34 of 2018.