100 – Serial Number Date Code Reference

Serial Number Date Code Reference (#100)

The first two characters of the serial number represent the year and month of manufacture. The remainder of the serial is a sequential production number, seven digits in length before December 2007 (DM), and eight digits in length after.

For example:

Production Year

Production Month

A = 1984 or 2004
B = 1985 or 2005
C = 1986 or 2006
D = 1987 or 2007
E = 1988 or 2008
F = 1989 or 2009
G = 1990 or 2010
H = 1991 or 2011
J = 1992 or 2012
K = 1993 or 2013

L = 1994 or 2014
M = 1995 or 2015
N = 1996 or 2016
P = 1997 or 2017
S = 1998 or 2018
T = 1999 or 2019
W = 2000 or 2020
X = 2001 or 2021
Y = 2002 or 2022
Z = 2003 or 2023

A=January
B=February
C=March
D=April
E=May
F=June

G=July
H=August
J=September
K=October
L=November
M=December

Production Year

A = 1984 or 2004
B = 1985 or 2005
C = 1986 or 2006
D = 1987 or 2007
E = 1988 or 2008
F = 1989 or 2009
G = 1990 or 2010
H = 1991 or 2011
J = 1992 or 2012
K = 1993 or 2013

L = 1994 or 2014
M = 1995 or 2015
N = 1996 or 2016
P = 1997 or 2017
S = 1998 or 2018
T = 1999 or 2019
W = 2000 or 2020
X = 2001 or 2021
Y = 2002 or 2022
Z = 2003 or 2023

Production Month

A=January
B=February
C=March
D=April
E=May
F=June

G=July
H=August
J=September
K=October
L=November
M=December

For the year column, we do not use the letters : I, O, Q, R U, V

For the month column we do not use the letters: I & N – Z

Due to a computer error there were some OA serial water heaters manufactured. They were built in January of 1997.

You accept the use of cookies as
described in our Privacy Policy