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Lennox family

How old is my Ducane heat pump?

Enter the serial number from the label. The date comes from Ducane's documented serial rules, not a guess.

Look for “Serial No.” or “S/N” on the label. Spaces and dashes are fine.

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How to read a Ducane heat pump serial number

  • Plant + year + month letter (Lennox since the 1970s; Allied brands since 1993)

    Example: 1611J19567 (Ducane) was made in September 2011. Lennox-family serials start with a two-digit plant code (16), then the year (2011) and a month letter ("J" = September; the letter I is skipped, so J is September).

Not decoded yet: Older all-numeric Ducane/Concord serials, pre-1973 Lennox and 1970s AirEase formats, and Lennox ductless units are not decoded yet.

Where to find the serial number

The rating plate is on the outdoor unit, usually on the side or back of the cabinet near the electrical disconnect.

The indoor air handler has its own plate and its own serial number, so check which unit you're decoding.

Ducane heat pump model numbers

If the brand name isn't visible on the label, the model number can help. Model numbers like these follow the Ducane / Concord nomenclature:

How long does a heat pump last?

A typical heat pump lasts about 10–15 years. That's a general estimate: maintenance, usage, climate and installation all matter, and age alone doesn't tell you a unit's condition.

Range from InterNACHI: standard estimated life expectancy chart, Carrier: how long do heat pumps last? and Lennox: how long do heat pumps last?.

Ducane heat pump recalls

No Ducane heat pump recalls were found in U.S. Consumer Product Safety Commission data when this page was checked (2026-09-29). A decoded result checks your model number live.

Questions

How can I tell how old my Ducane heat pump is?
Find the serial number on the rating plate and enter it above. Ducane heat pumps use the Lennox family serial format, which includes the manufacture date. For example, 1611J19567 was made in September 2011: Lennox-family serials start with a two-digit plant code (16), then the year (2011) and a month letter ("J" = September; the letter I is skipped, so J is September).
Where is the serial number on a Ducane heat pump?
The rating plate is on the outdoor unit, usually on the side or back of the cabinet near the electrical disconnect. The indoor air handler has its own plate and its own serial number, so check which unit you're decoding.
How long does a heat pump usually last?
A typical service life is about 10–15 years. That's a general estimate: maintenance, usage, climate and installation all matter, and age alone doesn't tell you a unit's condition.
Do Lennox, Armstrong Air, AirEase and Concord heat pumps use the same serial format?
Yes. Ducane, Lennox, Armstrong Air, AirEase and Concord use the same serial-number conventions (Lennox family), so the same decoding rules apply.
How reliable is the result?
The Lennox family rules come from documented sources, but they're in Beta while we check more real-world examples, so results are capped at medium confidence. If a serial doesn't match a documented format, we say so instead of guessing.

Same serial format: Lennox heat pump, Armstrong Air heat pump, AirEase heat pump, Concord heat pump

Other Ducane equipment: furnace, air conditioner

Sources

Rules last reviewed 2026-09-28. These rules are in Beta while we verify more real-world examples, so results are capped at medium confidence.

Manufacture dates are decoded from manufacturer serial-number conventions and available documentation. Serial formats can change. Verify critical equipment information with the manufacturer when necessary.