Determine the Age of Your Water Heater

Determine the Age of Your Water Heater

Understanding the age of your water heater can be crucial when it comes to maintaining your home’s hot water supply. The lifespan of a water heater can vary, but knowing its age can help you anticipate when it might be time for a replacement. If you’re unsure how to determine the age of your water heater, we’re here to help.

A.O. Smith Water Heaters


AO Smith water heaters in Kansas City.

A.O. Smith water heaters often have the date stamped on the label next to the model and serial number. If it’s not explicitly displayed, it’s usually embedded in the serial number. Here are the possible formats:

  • Style 1a: The third and fourth digits of the serial number denote the year of manufacture. For instance, in the serial number 1210A002243, the water heater was made in 2010.
  • Style 1b: Similar to Style 1a, the third and fourth digits represent the year. For example, in serial number S1318F000046, the water heater was made in 2018.
  • Style 1c: In this style, the first and second digits denote the year. For example, in serial number 1836111786352, the water heater was made in 2018.
  • Style 2: The first two digits represent the year. For example, in serial number AF04A093001, the water heater was made in 2004.
  • Style 3: The first two digits denote the year. For example, in serial number CG03-1495366-S29, the water heater was made in 2003.
  • Style 4: The first and second digits represent the year. For instance, in serial number E07A135491, the water heater was made in 2007.

Bradford White Water Heaters


Bradford white hot water heaters

The manufacture date for Bradford White water heaters is coded in the serial number. The first letter represents the year and the second letter represents the month. Here’s how to decode:

Year Codes:

  • 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

Month Codes:

  • A = January
  • B = February
  • C = March
  • D = April
  • E = May
  • F = June
  • G = July
  • H = August
  • J = September
  • K = October
  • L = November
  • M = December

State Select Water Heaters


Overland Park water heater replacement of State Select water heater.

State Select water heaters have the manufacture date embedded in the serial number. Here are the formats:

  • Style 1: The first four digits are the year and the week of the year. For example, in serial number 1210A002243, the water heater was made on the 10th week of 2012.
  • Style 2: Similar to Style 1, the first four digits represent the year and the week of manufacture. For example, in serial number H765662231, the water heater was made on the 5th week of 1976.
  • Style 3: The first two digits denote the year, and the following two digits are the week of the year. For instance, in serial number AF04A093001, the water heater was made on the 4th week of 2009.
  • Style 4: The first four digits represent the year and the week of the year. For instance, in serial number 1735107397129, the water heater was made on the 35th week of 2017.

Rheem Water Heaters


Rheem water heaters in Overland park, olathe, lenexa, and Shawnee.

Rheem water heaters embed the manufacture date within the serial number. It might be a little more complex due to the different styles they use, but with this guide, you can easily determine the age of your water heater:

  • Style 1: The second and third characters represent the month and the fourth and fifth characters represent the year. For example, in serial number R0884B10488, the water heater was made in August of 1984.
  • Style 2: The second and third characters represent the month and the fourth and fifth characters represent the year. For example, in serial number RHLN0106534307, the water heater was made in January of 2006.
  • Style 3: The second and third characters represent the week and the fourth and fifth characters represent the year. For instance, in serial number A141511869, the water heater was made on the 14th week of 2015.
  • Style 4: The second character represents the month and the third and fourth characters represent the year. For instance, in serial number D1114A441408265A, the water heater was made in November of 2014.
  • Style 5: The fifth and sixth characters represent the month and the seventh and eighth characters represent the year. For instance, in serial number RHNG0804P000036, the water heater was made in August of 2004.
  • Style 6: This style is for tankless water heaters, and the first two characters represent the month and the third and fourth characters represent the year. For instance, in serial number 05.05-000021, the water heater was made in May of 2005.
  • Style 7: The second and third characters represent the week and the fourth and fifth characters represent the year. For instance, in serial number RHUNM181401735, the water heater was made on the 18th week of 2014.

Please keep in mind that the prefix may vary and can be R, RH, RHLN, RHNG, RU, etc. Always remember to consult with a professional if you have any doubts or concerns about the condition of your water heater. If you think there may be an error in the information provided or if you have a brand, model, or serial number format that has not been addressed, please don’t hesitate to contact us. We appreciate all pertinent information, including clear and legible pictures of data/nomenclature plates.

Ruud Water Heaters


Ruud water heaters

The manufacture date for Ruud water heaters is also embedded within the serial number. Here’s how to decode:

  • Style 1: The second and third characters represent the month, and the fourth and fifth characters represent the year. For example, in serial number RU0904B21710, the water heater was made in April of 2009.
  • Style 2: Similar to Style 1, the second and third characters represent the month, and the fourth and fifth characters represent the year. For example, in serial number RHLN0106534307, the water heater was made in June of 2010.
  • Style 3: The first two characters represent the year and the third and fourth characters represent the week of the year. For example, in serial number A141511869, the water heater was made on the 15th week of 2014.
  • Style 4: The second and third characters represent the month, and the fourth and fifth characters represent the year. For example, in serial number D1114A441408265A, the water heater was made in November of 2014.
  • Style 5: The fifth and sixth characters represent the month, and the seventh and eighth characters represent the year. For example, in serial number RHNG0804P000036, the water heater was made in April of 2008.
  • Style 6: The first two digits represent the month, and the following two represent the year. For instance, in serial number 05.05-000021, the water heater was made in May of 2005.

Rinnai Water Heaters


Rinnai tankless water heaters

The manufacture date for Rinnai water heaters can be identified within the serial number:

  • Style 1: The third and fourth characters represent the month, and the fifth and sixth characters represent the year. For example, in serial number BL.CA-051306, the water heater was made in May of 2013.
  • Style 2: The first two digits represent the month, and the following two represent the year. For instance, in serial number 04.03-102521, the water heater was made in March of 2004.

Knowing how to decode the manufacture date from your water heater’s serial number can help you determine its age and anticipate when it might be time for a replacement

Navien Water Heaters


tankless water heater kansas city

Navien water heaters also embed the manufacture date within the serial number. Here’s how to decipher it:

  • Style 1: The first two characters represent the year, the third and fourth characters represent the month, and the fifth and sixth characters represent the day. For example, in serial number 9545J1152752044, the water heater was made on the 27th day of May in 2011.
  • Style 2: The first two characters represent the year. For example, in serial number 7414C14X1771143, the water heater was made in 2014.
  • Style 3: The fifth and sixth characters represent the year, the seventh and eighth characters represent the month, the ninth and tenth characters represent the day. For example, in serial number 9262-20081208-1027, the water heater was made on the 8th day of December in 2008.
  • Style 4: The fifth and sixth characters represent the year, the seventh and eighth characters represent the month, and the ninth and tenth characters represent the day. For instance, in serial number 9010-2008–114-1014, the water heater was made on the 14th day of January in 2008.

This guide should help you determine the age of your water heater based on its brand and serial number. Always remember to consult with a professional if you have any doubts or concerns about the condition of your water heater.