How old is my York air conditioner?

Serial number age decoder for York central air conditioners: 2 format eras, the decode rule in plain English, transcribed tables, and the official lookup.

• York air conditioner serial numbers in the 2004 to present format encode the year as digit 2 + digit 4 concatenated (0+5 = 2005) and the month as letter 3 (table below) (source: building-center.org).
• Example: serial W0K5896070 decodes to September 2005.
• York air conditioner serial numbers in the 1971 to 2004 format encode the year as letter 3 via 21-letter table (table below) and the month as letter 2 (A-N, I/J skipped like style 1) (source: building-center.org).
• Example: serial WAKM011379 decodes to 1980 or 2001 (January).
• The 1971 to 2004 format is ambiguous: Letters A-N repeat (1971-1984 vs 1992-2004): 21-year cycle. Some serials carry a parenthesized leading letter e.g. (S)EBHM062202 - ignore it. Style ran to Oct 2004, so 2004 has BOTH styles.
• York's official lookup at york.bosch-hcgroup.com returns warranty details ('HVAC WARRANTY LOOKUP').

Format eras

• 2004 to present VERIFIED
  A#A#######digit 2 + digit 4 concatenated (0+5 = 2005)
• 1971 to 2004 VERIFIED
  AAAA######letter 3 via 21-letter table: A=1971/1992 B=1972/1993 C=1973/1994 D=1974/1995 E=1975/1996

How to read the serial

2004 to present formatVERIFIED

Shape A#A####### · example W0K5896070 · confidence high

Year

digit 2 + digit 4 concatenated (0+5 = 2005)

Week or month

month = letter 3: A=Jan B=Feb C=Mar D=Apr E=May F=Jun G=Jul H=Aug K=Sep L=Oct M=Nov N=Dec

Plant

letter 1: A=Apodaca N=Norman S=Source One W=Wichita

Example: serial W0K5896070 decodes to September 2005.

1971 to 2004 formatVERIFIED

Shape AAAA###### · example WAKM011379 · confidence high

Year

letter 3 via 21-letter table: A=1971/1992 B=1972/1993 C=1973/1994 D=1974/1995 E=1975/1996 F=1976/1997 G=1977/1998 H=1978/1999 J=1979/2000 K=1980/2001 L=1981/2002 M=1982/2003 N=1983/2004 P=1984 R=1985 S=1986 T=1987 V=1988 W=1989 X=1990 Y=1991

Week or month

month = letter 2 (A-N, I/J skipped like style 1)

Plant

letter 1: A=Addison B=Blackville C=Canada D=Medina E=Elyria M=Madville N=Norman W=Wichita X=Mexico Y=York

Example: serial WAKM011379 decodes to 1980 or 2001 (January).

Where the data plate is on an air conditioner

On the outdoor condenser: a metal or foil plate on the side or back of the cabinet, often near the refrigerant line connections. Some brands repeat it inside the electrical access panel.

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 Air Conditioner (central) at 7 to 15 years of expected service (nachi.org). That chart is a guideline, not a prediction for your unit.

Sources

• https://www.building-center.org/york/
• img: YORK-Serial-Number-Style-1.jpg (transcribed)
• img: YORK-Serial-Number-Style-2.jpg (transcribed)
• https://york.bosch-hcgroup.com/residential-equipment/warranty-and-registrationofficial

Frequently asked questions

How do I tell the age of a York air conditioner from the serial number?

In the 2004 to present format the year is digit 2 + digit 4 concatenated (0+5 = 2005) and the month as letter 3 (table below). Example: serial W0K5896070 decodes to September 2005.

Where is the serial number on a York air conditioner?

On the data plate. On the outdoor condenser: a metal or foil plate on the side or back of the cabinet, often near the refrigerant line connections. Some brands repeat it inside the electrical access panel.

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