York furnace and AC age by serial number
York serial numbers changed in October 2004: newer serials split the year around a month letter, and older ones use letters for both month and year. This York serial number lookup shows every York manufacture date a serial could mean.
Where do I find the serial number?
York furnaces have the rating plate inside the cabinet, often on the side wall above the blower. On outdoor York condensers and heat pumps the plate is on the side or rear panel. Read it carefully, since York serials mix letters and numbers.
How to read a York serial number
A York serial from October 2004 on has ten characters: a plant letter, a year digit, a month letter, a second year digit, then six digits. In W0K5896070 the year digits are 0 and 5 and K is the month, so it reads as September 2005. Before that, York serials started with four letters, the second for the month and the third for the year.
Plant letter, year digit, month letter, year digit, sequence
- Used
- October 2004 to present
- Format
- Plant letter, year digit, month letter, year digit, sequence
- Example
- W0K5896070
- Months
- A to N, with I and J skipped. K is September, N is December.
Example, read
The year is split across the second and fourth characters, with the month letter between them.
Four letters then six digits: month is the 2nd letter, year the 3rd
- Used
- 1971 to September 2004
- Format
- Four letters then six digits: month is the 2nd letter, year the 3rd
- Example
- WAKM011379
- Years
- A 1971 or 1992, B 1972 or 1993, C 1973 or 1994, D 1974 or 1995, E 1975 or 1996, F 1976 or 1997, G 1977 or 1998, H 1978 or 1999, J 1979 or 2000, K 1980 or 2001, L 1981 or 2002, M 1982 or 2003, N 1983 or 2004, P 1984, R 1985, S 1986, T 1987, V 1988, W 1989, X 1990, Y 1991.
- Months
- A to N, with I and J skipped. K is September, N is December.
Example, read
Two possible years
Year letters A to N were used twice, 21 years apart, so most of these serials have two possible years. We show both.
Where to find the serial number
York furnaces have the rating plate inside the cabinet, often on the side wall above the blower. On outdoor York condensers and heat pumps the plate is on the side or rear panel. Read it carefully, since York serials mix letters and numbers.
Questions
How old is my York furnace or AC?
If it starts with a letter followed by a digit, read the second and fourth characters as the year and the third as the month. N0D6653823 reads as April 2006.
Why does my older York serial show two dates?
The year letters on pre-2004 York units were reused 21 years apart, so most of them can mean two years. WAKM011379 could be January 2001 or January 1980. The condition of the unit usually tells you which.
Which letters stand for which months on a York?
A to H are January to August. York skips both I and J, so K, L, M and N are September to December.
Can I use this for Coleman or Luxaire?
Coleman and Luxaire use the same serial format as York, but they do not have their own pages here yet.
Is the York date when the unit was built?
Yes. It is the manufacture date, not the day it went in. The two can be months apart.
Can I look up a York model number here?
No. York model numbers describe the equipment type, capacity and efficiency, not the build date, so we decode serials only.