How old is my Rheem water heater?

Type the serial number from the Rheem label to see when it was built.

Example

Q121561200

QPlant: Q = Nuevo Laredo, Mexico
12Week: 12 (around March)
15Year: 15 = 2015

Built Week 12 of 2015 (around March)

11 years, 7 months old

In replacement window. Inside the usual 6 to 12 year lifespan, so replacement could come any time. Worth budgeting for it.

What to do now

Get a replacement quote now, while there is no emergency. Prices are better when you can compare.
Check the floor around the base and the pipe fittings on top for moisture or rust every few months.
Know where the cold water shutoff above the tank is, so you can stop a leak quickly.
Some home insurers ask the age of the water heater, and in Florida a 4-point inspection flags tanks over 10 years. Check before you renew or buy a house.
Tank warranties usually run 6 to 12 years. Coverage usually counts from the install date or from a few months after the build date, so the build date is a good guide.

How this was read

Q is the plant letter (Nuevo Laredo, Mexico).
The next two digits, 12, are the week of the year.
The two digits after that, 15, are the year: 2015.

Format: Rheem plant letter, week and year. Sources: Rheem service bulletin TSB 1207 (PDF), Rheem: reading your serial number, CPSC 2016 Rheem recall.

Reading a Rheem serial number

Rheem has used two main serial formats. Units built before about 2012 start with the month and year as four digits. Newer units start with a plant letter, then the week and the year.

Rheem’s own website still only describes the older month-and-year format. Its 2012 service bulletin documents the switch, and the checker reads both.

About Rheem

Brothers Richard and Donald Rheem started the company in Emeryville, California, in 1925. It first made galvanized steel drums.
Rheem became a wholly owned subsidiary of Paloma Industries of Japan in 1988.
In 1999 Rheem said its Rheem and Ruud water heaters were for professional contractors only. In 2012 it began selling Rheem-branded water heaters at The Home Depot.
Rheem moved its headquarters to Atlanta, Georgia, in 2007.

Sources: Rheem 100, Rheem to Manufacture G.E. Water Heaters (Supply House Times, 1999), History of Paloma Industries Ltd. (FundingUniverse)

Rheem plant letter, week and year

Used 2012 to today. Example: Q121561200

Newer Rheem, Ruud and Richmond serials start with a plant letter (A, C, M, Q or W), then the week (2 digits), then the year (2 digits), then a 5-digit number. Rheem switched plants to this format from April 2012. Some older guides, including Rheem’s own website, still describe only the month-year format.

Worked example: Q121561200 was built Week 12 of 2015 (around March), so it is 11 years, 7 months old as of October 2026.

Plant letter
Letter	Plant
A	Montgomery, Alabama
W	Water Heater Innovations
Q	Nuevo Laredo, Mexico
M	Mexicali, Mexico
C	Canada

Sources: Rheem service bulletin TSB 1207 (PDF), Rheem: reading your serial number, CPSC 2016 Rheem recall

Rheem month and year

Used through about 2014. Example: RHLN0205A20589

Older serials put the month (2 digits) and year (2 digits) first, after any product letters like RH, RN or GE. A plant letter and a running number follow, like RHLN 0205A20589 for February 2005.

Worked example: Q121561200 was built December 2015, so it is 10 years, 10 months old as of October 2026.

Sources: Rheem service bulletin TSB 1207 (PDF), Rheem: reading your serial number, CPSC 2016 Rheem recall

Rheem recalls

Recalls from the U.S. Consumer Product Safety Commission that name Rheem. Whether a unit is included depends on its model and build date; the checker above flags matches.

Year	Recall	Hazard
2016	Rheem Performance Platinum electric water heaters	The control panel can overheat and start a fire.
2007	Rheem, Ruud, Richmond and Paloma power vent tankless water heaters	Dust can build up if the filter door is off, which can cause carbon monoxide.
2005	Robertshaw R110 gas valves on water heaters	Screws on the gas valve can break and leak gas, which can cause a fire or explosion.

Standing at the unit? Use your phone

Point your phone’s camera at this code. The scanner opens and reads the label for you.

Same serial number format as Rheem: GE, Kenmore, Richmond, Ruud.

How old is my Rheem furnace or AC?

Formats on this page were last checked against their sources in October 2026. Rheem is a trademark of its owner. This page is independent and not affiliated with or endorsed by Rheem. For warranty questions, contact Rheem directly.

Where the serial is on a Rheem

Rheem puts the rating label on the front of the tank above the gas valve or the upper element cover. Newer labels also print "MFG. DATE" near the serial.

The label is a sticker on the side of the tank, usually above the gas valve or the upper thermostat cover. On units squeezed into a closet it often faces the wall, so a phone photo is easier than reading it by eye.