SerialAtlas
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HVAC date-code guide

Ducane serial number lookup

Ducane is an Allied Air brand. Modern serials commonly use the same year digits and month-letter positions found across related Lennox-built equipment.

Parent
Lennox International / Allied Air
Common code
For the common current style, characters 3–4 are the year and character 5 is a month letter.
Reviewed
August 8, 2026

Instant equipment lookup

Decode the manufacturing date

Runs on this device
Equipment type

Using For the common current style, characters 3–4 are the year and character 5 is a month letter.

Type exactly what is printed. Spaces and dashes are ignored.

Optional: add model number for capacity cluesAdd model

Model decoding is labeled as a clue unless the exact format is documented.

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EQUIPMENT DATA
MODEL24ABC636A003
SERIAL5019X30312
WeekYear

See exactly how the code was read

SerialAtlas highlights the date characters, names the matching rule, and shows alternative interpretations when the code is ambiguous.

  • Current age calculated automatically
  • Confidence and rule source shown
  • Optional model-capacity clue

Evidence-led route update

Ducane date-code evidence

If you need to estimate a Ducane unit’s manufacture age, use the year and month-letter positions documented for the Allied Air family.

Read the Allied Air month letter with the year positions

For the common current style, characters 3–4 are the year and character 5 is a month letter. Ducane is an Allied Air brand represented by the verified Lennox-family characters 3–5. That family connection explains the rule without treating Ducane’s model and support records as Lennox records. Ducane is represented by the Lennox/Allied Air family, where the verified characters 3–5 combine year digits with a month letter. The Ducane label and equipment type remain the first identity check.

Worked example: 5196G12345

5196G12345 — The verified decoder reads this fixture as July 1996. The date is a manufacture estimate, not an installation date.

When a Ducane label needs an era check

Allied Air labels can change by era, product line, and market. If the serial does not fit the documented positions, retain the full plate and use official support instead of applying a generic HVAC rule.

Model number vs. serial number

Use the Ducane model for product-family context and the serial for age; provide both for parts or coverage review. Photograph the rating plate on the furnace, condenser, heat pump, or air handler and keep the model beside the serial.

Limits and official support

Allied Air labels can vary by era, product line, and market. If the result affects warranty, registration, parts, safety, or replacement decisions, use the complete model and serial with the manufacturer or a qualified professional. SerialAtlas is an independent reference, not an official warranty lookup or warranty coverage decision.

Open Ducane support route

How to read a Ducane serial number

For the common current style, characters 3–4 are the year and character 5 is a month letter. SerialAtlas removes spacing and punctuation, then applies only the documented rule families mapped to Ducane. The lookup remains in the browser.

Try this documented-style example5196G12345Load example

Equipment covered

  • air conditioners
  • heat pumps
  • furnaces
  • air handlers
  • packaged systems

Commercial, imported, very old, specialty, and private-label equipment can use a different code. Confirm the full rating plate before accepting a result.

Where to find the rating plate

  • Outdoor condenser or heat-pump cabinet, usually near the service valves
  • Inside the furnace or air-handler access panel
  • On the packaged-unit rating plate
  • Near the electrical disconnect or wiring diagram

Why more than one date can appear

Two-digit years and repeating letter cycles can point to more than one era. SerialAtlas ranks the plausible dates but keeps materially different alternatives visible. Label design, refrigerant, installation records, and product literature can resolve the era.

Source and verification

Inspector Handbook open reference data (CC BY 4.0). Independently implemented and reviewed August 8, 2026.

Open reference source

What this result does not prove

A manufacture date is not an installation date, warranty decision, recall match, condition assessment, or replacement recommendation. Confirm high-stakes decisions with the manufacturer or a qualified professional.