How To Determine the
Age of Your Water Heater
The serial number's primary purpose is to indicate the date of manufacture of the water heater, but not all water heaters use the same formatting. What follows are four major types of tank water heaters (others will likely be similar):
The first
letter indicates the MONTH of manufacture.
The 2nd and 3rd digits indicate the YEAR of manufacture.
A =January
B =February
C =March
D =April
E =May
F =June
G =July
H =August
I =September
J =October
K =November
L =December
91 =1991
92 =1992
93 =1993
94 =1994
95 =1995
96 =1996
97 =1997
98 =1998
99 =1999
00 =2000
01 =2001
02 =2002
SERIAL NUMBER
EXAMPLE:
C = March, 00 = 2000
This serial number indicates this model was built March, 2000.
The serial
number is alpha numeric (has letters & numbers).
The first letter determines the plant where the water heater was manufactured.
The second letter represents the month the heater was manufactured.
There will be a combination of numbers following the first two letters. This number is the year the heater was manufactured. For example:
MB951234567-232 was manufactured in February of 1995.
GK940012345-915 was manufactured in October of 1994.
A = January
B = February
C = March
D = April
E = May
F = June
G = July
H = August
J = September
K = October
L = November
M = December
The first four numbers tell you the age of the water heater. The first two numbers are the month and the next two are the year it was manufactured. In this example this water heater was manufactured in April of 1997.
The 1st letter is the year of manufacture.
A = 1984
B = 1985
C = 1986
D = 1987
E = 1988
F = 1989
G = 1990
H = 1991
J = 1992
K = 1993
L = 1994
M = 1995
N = 1996
P = 1997
S = 1998
T = 1999
W = 2000
X = 2001
Y = 2002
Z = 2003
The 2nd letter is the month of manufacture.
A = January
B = February
C = March
D = April
E = May
F = June
G = July
H = August
J = September
K = October
L = November
M = December
The first two numbers are the year it was manufactured and the second two number are the week within that year that it was manufactured. For example, if the first 4 digits of the serial number are 9932, then it was manufactured in the 32 week of 1999.