Installation / Operation Instruction Manual

3
Determining the Age of Your Water Heater
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:
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.
NOTICE
This Service Manual is for all LE / SLE models YG and later. For 65, 80,
and 120 gallon models, this manual covers YF and later.
Production Month
A = January
G = July
B = February
H = August
C = March
J = September
D =April
K = October
E = May
L = November
F = June
M = December
Production Year
A = 1984 or 2004
L = 1994 or 2014
B = 1985 or 2005
M = 1995 or 2015
C = 1986 or 2006
N = 1996 or 2016
D =1987 or 2007
P = 1997 or 2017
E = 1988 or 2008
S = 1998 or 2018
F = 1989 or 2009
T = 1999 or 2019
G = 1990 or 2010
W = 2000 or 2020
H = 1991 or 2011
X = 2001 or 2021
J = 1992 or 2012
Y =2002 or 2022
K = 1993 or 2013
Z = 2003 or 2023