How Old is My Water Heater?
This article is a quick reference guide for the most common manufacturers of water heaters (and boilers). Most manufacturers of water heaters do not clearly state the manufacture year on the data plate or label but luckily the year of manufacture is typically coded in the serial number. By referencing the manufacturer below with the serial number the age of the equipment can be determined in most cases..
Manufacturers have been inconsistent with their labeling over the years, which is why buyers should verify this information by following up with the manufacturer. A lot of information can be included in the serial number including the month of manufacture, day of manufacture, manufacture plant, type of unit, and more. When it comes to determining a unit’s life expectancy, we are most interested in the year of manufacture, which is the focus of this article.
Water Heaters typically have a 15-20 year life expectancy. Their service life can be extended by replacing the heating elements and other components.
How old is my American water heater?
How old is my AO Smith water heater?
How old is my Apollo water heater?
How old is my Bosch water heater?
How old is my Bradford White water heater?
How old is my General Electric or GE water heater?
How old is my GSW water heater?
How old is my Navien water heater?
How old is my PowerStar water heater? See Bosch
How old is my Rheem water heater?
How old is my Ruud water heater?
How old is my Rinnai water heater?
How old is my State Industries water heater?
How old is my Takagi water heater?
How old is my US Craftmaster water heater?
How old is my Weil-McLain boiler?
How old is my Whirlpool water heater?
Water Heaters
American
See AO Smith
AO Smith
Y=year of manufacturer X=letter 7=numbers
The year of manufacture for AO Smith water heaters is encoded in the serial number.
YY77X7777777 (1st and 2nd numbers of the serial number indicate the year of manufacture)
YY777 77777 (1st and 2nd numbers of the serial number indicate the year of manufacture)
YY77777777777 (1st and 2nd numbers of the serial number indicate the year of manufacture)
Note: Older units may have additional letters before the 1st and 2nd numbers
Apollo
Y=year of manufacturer X=letter 7=numbers
The year of manufacture for Apollo water heaters is encoded in the serial number.
XYYX77777 (1st and 2nd numbers of the serial number indicate the year of manufacture)
Note: Older units may have additional letters before the 1st and 2nd numbers
Bosch
Y=year of manufacturer X=letter 7=numbers
The year of manufacture for Bosch water heaters is encoded in the serial number.
Note: Some models cannot be identified by the serial number. You must call Bosch at 800 283-3787
Bosch has an online resource for dating water heaters that can be found here
First number may be the last number of the year. The decade can be assumed or use the key below…
YYY777777 (First three numbers are a code – see code key below)
XXYYY777777 (First three numbers after the first two letters are a code – see code key below)
1998 (numbers 861-872)
1999 (numbers 961-972)
2000 (numbers 081-092)
2001 (numbers 181-192)
2002 (numbers 281-292)
2003 (numbers 381-392)
2004 (numbers 481-492)
2005 (numbers 581-592)
2006 (numbers 681-692)
2007 (numbers 781-792)
2008 (numbers 881-892)
2009 (numbers 981-992)
Bradford White
Y=year of manufacturer X=letter 7=numbers
The year of manufacture for Bradford White water heaters is encoded in the serial number.
YX7777777 (The 1st letter of the serial number indicates the year of manufacture)
A=2004 B=2005 C=2006 D=2007 E=2008 F=2009 G=1990/2010 H=1991/2011 J=1992/2012 K=1993/2013 L=1994/2014
M=1995/2015 N=1996/2016 P=1997/2017 S=1998/2018 T=1999/2019 W=2000/2020 X=2001/2021 Y=2002/2022 Z=2003/2023
General Electric or GE
Y=year of manufacturer X=letter 7=numbers
The year of manufacture for General Electric water heaters is encoded in the serial number.
77YY000000 (3rd and 4th numbers of the serial number indicate the year of manufacture)
XX77YY777777 (3rd and 4th numbers of the serial number indicate the year of manufacture)
Gas units: GENG 77YYX77777 (3rd and 4th numbers of the serial number indicate the year of manufacture)
GSW
See AO Smith
Navien
Y=year of manufacturer X=letter 7=numbers
The year of manufacture for Navien water heaters is encoded in the serial number.
7777XYY77777777 (5th and 6th numbers after a letter of the serial number indicate the year of manufacture)
7777XYYX7777777 (5th and 6th numbers after a letter of the serial number indicate the year of manufacture)
7777-YYYY7777-7777 (5th, 6th, 7th, and 8th numbers of the serial number indicate the year of manufacture)
7777-YYYY-777-7777 (5th, 6th, 7th, and 8th numbers of the serial number indicate the year of manufacture)
Rheem or Ruud
Y=year of manufacturer X=letter 7=numbers
The year of manufacture for Rheem/Ruud water heaters is encoded in the serial number.
X77YYX7777777777X (3rd and 4th numbers after a letter of the serial number indicate the year of manufacture)
Tankless YY.77-777777 (1st and 2nd numbers after a letter of the serial number indicate the year of manufacture)
Rinnai
Y=year of manufacturer X=letter 7=numbers
The year of manufacture for Rinnai water heaters is encoded in the serial number.
2009 and later Y7. CA-777777 (1st letter of the serial number indicates the year of manufacture)
A=2009 B=2010 C=2011 D=2012 E=2013 F=2014 G=2015 H=2016 J=2017 K=2018 L=2019 M=2020 N=2021 P=2022 Q=2023
before 2009 YY. 77-77777 (1st and 2nd numbers of the serial number indicate the year of manufacture)
State Industries
Y=year of manufacturer X=letter 7=numbers
The year of manufacture for State Industry water heaters is encoded in the serial number.
YY77X777777 (1st and 2nd numbers of the serial number indicate the year of manufacture)
— or —
XYY77 X777777 (1st and 2nd numbers after first letter)
Takagi
Call 888 882 5244 with the serial number.
US Craftmaster
Y=year of manufacturer X=letter 7=numbers
The year of manufacture for US Craftmaster water heaters is encoded in the serial number.
YY7777777 (1st and 2nd numbers of the serial number indicate the year of manufacture)
Whirlpool
Y=year of manufacturer X=letter 7=numbers
The year of manufacture for Whirlpool water heaters is encoded in the serial number.
YY77X777777 (1st and 2nd numbers of the serial number indicate the year of manufacture)
Note: Serial numbers may or may not have a letter.
Boilers
How Old Is My Boiler?
Most manufacturers of boilers do not clearly state the manufacture year on the data plate or label but luckily the year of manufacture is typically coded in the serial number. By referencing the manufacturer below with the serial number the age of the equipment can be determined in most cases.
Weil McLain
The CP number is found on a white sticker on the boiler. The year of manufacture for Weil McLain boilers is encoded in the CP number. Or call 219 879-6561 or 866 783-9276. The company also has a CP number lookup page here.
Pre- 2000 — 1414001-3810000
2000 — 3810001-4055000
2001 — 4055001-4311000
2002 — 4311001-4586999
2003 — 4587000-4807000
2004 — 4807001-5047000
2005 — 5047001-5301000
2006 — 5301001-5454497
2007 — 5454498-5721063
2008 — 5731064-5957346
2009 — 5957347-6150483
2010 — 6150484-6368018
2011 — 6368019-6555277
2012 — 6555278-6779489
2013 — 6779490-6998292
2014 — 6998293-7209932
2015 — 7209933-7429423
2016 — 7429424-7493025
2017 — 7493026-7629669
2018 — 7629670-7729057
2019 — 7729058-7782025
2020 — 7782026-7880529
2021 — 7880530-7961367
2022 — 7961368-