Since you probably understand that appliances don’t last forever, one of the first questions you’ll ask yourself when something goes wrong is, “How old is my water heater?“.
You may be wondering if repair or replacement is the best option or even if you’re still covered by the manufacturer’s warranty.
If you’re the type who saves every purchase receipt for decades, you probably don’t need to read this. If you have a newer model, please note the water heater age is sometimes clearly printed on the manufacturer’s label affixed to the unit.
For everyone else, keep reading to see how easy it is to find your water heater’s manufacture date. All you need is to know who manufactured the water heater and its serial number (both found on the label affixed to the water heater).
Alternatively, you can check your manual to help determine age of a water heater based on the copyright year. You can access online versions of most models of the three most popular brands at these links:
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Manufacturer vs Brand
Before going further, I want to point out the differences between a water heater manufacturer and a water heater brand. The manufacturer (residential water heaters) is the company that takes materials or components to create (or manufacture) the water heater.
The brand on the other hand is what the water heater is sold (or branded) as to customer. A small number of manufacturers create water heaters which are then sold under dozens of different brands. For instance, even though the water heater you bought from Sears says Kenmore on it, it’s still manufactured by Rheem water heaters.
So, how old IS my water heater?
Below are the water heater serial number lookup sections for every major water heater manufacturer. Column one lists all the various brands that manufacturer makes, column two shows sample serial numbers, and column three of each table acts as a serial number decoder.
A.O. Smith Water Heater Age
| Included Brands | A.O. Smith Serial Numbers | How to Decode |
|---|---|---|
| A.O. Smith Glascote GSW PermaGlas | Style 1 (current): 1510******* (10th week of 2015) Style 2 (pre-2008): *A07******* (January, 2007) | Style 1: Digits 1-2 are the year and digits 3-4 are the week of the year. Style 2: The second digit is the month (A-N, excluding I) so A=January and N=December. Digits 3-4 are the year. |
Rheem Water Heater Age
| Included Brands | Rheem Serial Numbers | How to Decode |
|---|---|---|
| Rheem Ruud Rheem/Ruud Richmond Vista Therm Citation Aqua Therm Energy Master Vanguard Cimarrom Coast to Coast Lowe’s Servi-Star True Value ABS Intertherm & Miller Mainstream Montgomery Ward General Electric Professional | Style 1: 0811****** (August, 2011) Style 2: *3210***** (32nd week of 2010) Style 3: ** 1599****** (15th week of 1999) Style 4: ****0608****** (June, 2008) Style 5: 09.04-****** (April, 2009) | Style 1: Digits 1-2 are the month and digits 3-4 are the year. Style 2: Digits 2-3 are the week of the year and digits 4-5 are the year. Style 3: Digits 3-4 are the week of the year and digits 5-6 are the year. Style 4: Digits 5-6 are the month and digits 7-8 are the year. Style 5: Digits 1-2 are the year and digits 3-4 are the month (the sets of numbers are separated by a period) |
Bradford White Water Heater Age
| Included Brands | Bradford White Serial Numbers | How to Decode |
|---|---|---|
| Bradford White Jetglas | EH******* (August, 2008) TB******* (February, 1999) | 1st letter equals the year using this key: P = 2017 | N = 2016 | M = 2015 L = 2014 | K = 2013 | J = 2012 H = 2011 | G = 2010 | F = 2009 E = 2008 | D = 2007 | C = 2006 B = 2005 | A = 2004 | Z = 2003 Y = 2002 | X = 2001 | W = 2000 T = 1999 | S = 1998 | P = 1997 2nd letter equals the month using this key: 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 Industries Water Heater Age
| Included Brands | State Ind. Serial Numbers | How to Decode |
|---|---|---|
| State/Kenmore Ace Ambassador Barnett Century Crosley Energy Stretcher Freedom Freedome/Nipsco Hardware House Master Plumber/True5 Mission Nationaline Patriot Penfield President Regency Reliance The Plumbery Thermo-Ki | Style 1: 1021******* (21st week of 2010) Style 2: K06******* (October, 2006) Style 3: *K06******* (October, 2006) | Style 1: Digits 1-2 are the year and digits 3-4 are the week of the year. Style 2: The 1st digit is the month of the year using the key below and digits 2-3 are the year. A = January | B = February | C = March D = April | E = May | F = June G = July | H = August | J = September K = October | L = November | M = December Style 3: Same as style 2 except it has an extra digit at the beginning. |
American Water Heater Age
Acquired by A.O. Smith in 2001. Prior to that, manufactured water heaters for dozens of different brands.| Included Brands | American Serial Numbers | How to Decode |
|---|---|---|
| American Water Heaters Ace American Hardware Best Best Deluxe Apex Aqua Temp Agua Therm Aquamatic Champion Craftmaster De-Limier Deluxe Eagle Earl’s Energy Saver Environtemp Four Most Hotmaster Hotstream King-Cleen King-line Master Plumber Mor-Flo/American Nationaline Neptune Penquin Premier Prestige Proline Proline-Plus Quaker Quick-Flo Raywall Revere Riveria SABH Sands Sentinel Service-Star Shamrock Special Deluxe Standard Super Eagle Sure-Fire Thoro-clean Tru-Test Tru Value U.S. Supply Whirlpool XCL-Energy Saver | Style 1 (current): 1510******* (10th week of 2015) Style 2 (pre-2008): *A07******* (January, 2007) | Style 1: Digits 1-2 are the year and digits 3-4 are the week of the year. Style 2: The second digit is the month (A-N, excluding I) so A=January and N=December. Digits 3-4 are the year. |
Lochinvar Water Heater Age
| Included Brands | Lochinvar Serial Numbers | How to Decode |
|---|---|---|
| Lochinvar Energy Saver Golden Knight Knight | EH******* (August, 2008) TB******* (February, 1999) | 1st letter equals the year using this key: P = 2017 | N = 2016 | M = 2015 L = 2014 | K = 2013 | J = 2012 H = 2011 | G = 2010 | F = 2009 E = 2008 | D = 2007 | C = 2006 B = 2005 | A = 2004 | Z = 2003 Y = 2002 | X = 2001 | W = 2000 T = 1999 | S = 1998 | P = 1997 2nd letter equals the month using this key: A = January | B = February | C = March D = April | E = May | F = June G = July | H = August | J = September K = October | L = November | M = December |
Summary
As a seasoned plumbing expert with over 30 years of experience, I know that determining the age of a water heater can be a daunting task. However, there are a few tips that I can offer to make the process easier for you.
Firstly, if you’re dealing with a tank-style water heater, you’ll typically find the year of manufacture on the Bradford White retain plate. This is a sticker located on the side of the water heater tank. The first letter of the serial number corresponds to the year of manufacture, and the second letter corresponds to the month. For example, if the first letter is “D,” the year of manufacture would be 2014. The following format is used for Bradford White Water Heater’s year decoder: 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, Q=1998, R=1999, S=2000, T=2001, U=2002, V=2003, W=2004, X=2005, Y=2006, A=2007, B=2008, C=2009, D=2010, E=2011, F=2012, G=2013, H=2014, J=2015, K=2016, L=2017, M=2018, N=2019, P=2020, Q=2021.
On the other hand, if you’re dealing with tankless water heaters or an A O Smith water heater, the serial number is often formatted differently. In some cases, a computer error can also result in a serial number that doesn’t follow the expected format. In these instances, you may need to contact the manufacturer directly to determine the age of the water heater.
Another thing to keep in mind is that the installation date isn’t always the same as the year of manufacture. For example, if a water heater was manufactured in early February but not installed until June of the same year, the installation date would be used to determine the age of the water heater.
In summary, determining the age of a water heater can be tricky, but by checking the retain plate and deciphering the serial number using the year decoder, you can often determine the year of manufacture. If you’re dealing with a different format or a computer error, contacting the manufacturer may be necessary to determine the age of the water heater.
Plumber Talk Q&A
Anthony (Water Heater Hub): Hello everyone, and welcome to this special interview. I’m Anthony from the Water Heater Hub. Today, I have Jay from the Plumber Trade Training Center with me. We’ll be discussing how to determine the age of a hot water heater. Hi Jay, glad you could join us.
Jay (Plumber Trade Training Center): Thanks for having me, Anthony. It’s great to be here to talk about something as crucial as understanding the age and maintenance of water heaters.
Anthony: Let’s dive right in. Our listeners are curious about different types of water heaters like tankless, Bradford White, heat pump water heaters, and so on. Can you shed some light on how to find out their ages?
Jay: Absolutely. The age of a water heater is essential for home inspections, understanding service life, and preventing water damage. Regardless of the type – be it Rinnai, Ruud, or others – the key is usually in the water heater’s serial number.
Anthony: Interesting. How does the serial number reveal the age?
Jay: Most water heaters, typically, have a serial number with either seven or eight digits. For instance, Bradford White water heaters have a unique way where the third and fourth digits indicate the year of manufacture.
Anthony: Could you give us an example?
Jay: Sure. Let’s say the serial number has ‘F09’ as its third, fourth, and fifth digits. This means it’s manufactured by Bradford White Corporation in either 1989 or 2009. The letter represents the year and the following two digits, the month of manufacture.
Anthony: That’s fascinating! So each letter corresponds to a specific year?
Jay: Exactly. For instance, ‘F’ stands for 1989 or 2009, ‘E’ for 1988 or 2008, ‘C’ for 1986 or 2006, and so on. It’s a sequential system.
Anthony: How about tankless water heaters, like those from Rinnai?
Jay: Tankless water heaters also follow a similar pattern, but it varies by brand. For Rinnai, the first two characters of the serial number might indicate the month and year of manufacture.
Anthony: Got it. So, knowing this, what would you say is the typical life expectancy of these water heaters?
Jay: That varies based on the type. Tankless water heaters often last longer than conventional ones. Routine maintenance is key. A well-maintained water heater can surpass its expected service life.
Anthony: That makes routine maintenance sound crucial.
Jay: Absolutely. Regular maintenance can prevent a lot of issues and extend the heater’s lifespan.
Anthony (Water Heater Hub): Welcome back. We’re continuing our discussion with Jay about determining the age of water heaters. Jay, you mentioned the serial number as a key factor. Could you elaborate on how this applies to other brands like Rinnai and Ruud?
Jay (Plumber Trade Training Center): Sure, Anthony. For Rinnai water heaters, the serial number often contains seven digits. These digits include a sequential production number that can help identify the age. For example, a serial number starting with ’12’ may indicate the unit was manufactured in December of a certain year.
Anthony: That’s straightforward. How about Ruud water heaters?
Jay: Ruud follows a similar pattern. The age can usually be determined by the first four digits of the serial number. The first two digits often represent the month, and the next two the year.
Anthony: Let’s talk about the alphanumeric codes you mentioned earlier, like ‘F’ for 1989 or 2009, ‘E’ for 1988 or 2008, and so on.
Jay: Those codes are critical for accurately dating a water heater. For example, a Bradford White heater with a serial number starting with ‘H’ could be from 1991 or 2011. ‘H’ represents the year and is followed by two digits that represent the month. So, ‘H06’ would mean June of either 1991 or 2011.
Anthony: That’s quite a unique system. Does this mean the water heaters have a 20-year ambiguity in their manufacture date?
Jay: In a way, yes. But when you combine this information with the typical life expectancy and physical condition of the heater, you can often narrow down the actual age.
Anthony: How about heaters with codes like ‘J’, ‘B’, ‘G’, and others?
Jay: Each letter corresponds to specific years. ‘J’ is for 1992 or 2012, ‘B’ for 1985 or 2005, ‘G’ for 1990 or 2010, and so on. This system continues alphabetically with ‘K’ for 1993 or 2013, ‘L’ for 1994 or 2014, and ‘N’ for 1996 or 2016.
Anthony: So, it’s a matter of understanding the code and then assessing the condition of the unit?
Jay: Exactly. It’s about putting the pieces together. Knowing the code is the first step, and then considering the heater’s overall condition and performance helps in determining its age.
Anthony: This has been very enlightening, Jay. I’m sure our listeners now have a better understanding of how to determine the age of their water heaters. Thank you for sharing your expertise.
Jay: It was my pleasure, Anthony. I’m glad to help.
Anthony: And thank you, listeners, for joining us. Remember, understanding the age of your water heater is key to ensuring its efficient operation and longevity.
