How old is my Allied Air furnace?

Serial number age decoder for Allied Air furnaces: 4 format eras, the decode rule in plain English, transcribed tables, and the official lookup.

• Allied Air furnace 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.
• Allied Air furnace serial numbers in the era not stated format encode the year as digits 3-4 = YY (4601J19567 = 2001; 1606B13871 = 2006; 4607B20058 = 2007) and the month as letter 5 (A=Jan .. M=Dec, I not used) (source: building-center.org).
• Example: serial 4601J19567 decodes to September 2001.
• Allied Air furnace serial numbers in the era not stated format encode the year as digits 7-8 = YY (4140720328 = 2003; 0183290431 = 2004) and the week as digits 9-10 (28; 31 = end of August) (source: building-center.org).
• Example: serial 4140720328 decodes to week 28 of 2003.

Format eras

• 1973 to present VERIFIED
  ####A#####digits 3-4 (YY)
• 1970 to 1977 VERIFIED
  ##A##AA###digits 4-5 = year REVERSED (67 = 1976)
• era not stated VERIFIED
  ####A#####digits 3-4 = YY (4601J19567 = 2001; 1606B13871 = 2006; 4607B20058 = 2007)
• era not stated VERIFIED
  ##########digits 7-8 = YY (4140720328 = 2003; 0183290431 = 2004)

How to read the serial

1973 to present formatVERIFIED

Shape ####A##### · example 5899L17212 · confidence high

Year

digits 3-4 (YY)

Week or month

month = letter at position 5 (A=Jan .. M=Dec, I skipped)

Plant

digits 1-2 = factory/plant code

Example: serial 5899L17212 decodes to November 1999.

Listed under Lennox in the source; Allied Air is named in that format's family and the corporate link is an estimate, not a checked fact.

1970 to 1977 formatVERIFIED

Shape ##A##AA### · example 15A67JA098 · confidence medium

Year

digits 4-5 = year REVERSED (67 = 1976)

Week or month

day = digits 1-2; month = letter 3 (A=Jan .. M=Dec, I skipped)

Plant

letter 6: J = Bellevue OH, A = Columbus OH (letter 7 'A' = n/a)

Example: serial 15A67JA098 decodes to January 1976.

era not stated formatVERIFIED

Shape ####A##### · example 4601J19567 · confidence high

Year

digits 3-4 = YY (4601J19567 = 2001; 1606B13871 = 2006; 4607B20058 = 2007)

Week or month

month = letter 5 (A=Jan .. M=Dec, I not used)

Plant

digits 1-2 = plant: 46 Blackville, 84 Bellevue, 16 Allied Orangeburg, 60 ADP, 56 Lennox

Example: serial 4601J19567 decodes to September 2001.

era not stated formatVERIFIED

Shape ########## · example 4140720328 · confidence high

Year

digits 7-8 = YY (4140720328 = 2003; 0183290431 = 2004)

Week or month

week = digits 9-10 (28; 31 = end of August)

Example: serial 4140720328 decodes to week 28 of 2003.

Where the data plate is on a furnace

Inside the furnace: remove the upper (burner) access door and look on the inside of the door, on the blower compartment wall, or on a sticker facing you at the burner deck.

General guidance, not brand-specific: the owner's manual or the installer can point to the exact spot. See the data plate guide.

For scale only: the InterNACHI Standard Estimated Life Expectancy Chart for Homes lists Furnace at 15 to 25 years of expected service (nachi.org). That chart is a guideline, not a prediction for your unit.

What we could not confirm

• Allied Air is treated as sharing Lennox's format because the source lists it in that family; the corporate relationship itself is an estimate.
• No official online lookup URL was verified for Allied Air.

Sources

• https://www.building-center.org/lennox/
• https://www.lennox.com/residential/owners/assistance/warranty/official
• https://www.building-center.org/concord-hvac-age/
• https://www.building-center.org/wp-content/uploads/2018/06/Concord-Style-2.png
• https://www.building-center.org/airease-hvac-age/
• https://www.building-center.org/ducane-hvac-age/
• https://www.building-center.org/armstrong-air-hvac-age/
• https://www.building-center.org/magic-pak-hvac-age/
• https://www.building-center.org/allied-commercial-hvac-age/
• https://www.building-center.org/aire-flo-hvac-age/
• https://www.building-center.org/wp-content/uploads/2023/12/Ducane-HVAC-style-1.jpg
• https://www.building-center.org/wp-content/uploads/2018/06/Concord-Style-1.png
• https://www.building-center.org/wp-content/uploads/2015/09/Style-3_Airease-Date-of-Manufacture_Serial-Number-Nomenclature1.png

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