Rheem water heater age by serial number
Rheem water heaters have carried their manufacture date in the serial number since 1978. There are 2 formats in the field; type yours and the decoder works out which one it is. Or read how the code works below and do it by hand.
The same code covers GE, Richmond and Ruud.
Example: Rheem water heater, serial Q111516703
Made Mid March 2015
11 years, 7 months old
The serial reads as week 11 of 2015 (About 2013 to today format). Made, not installed: most units go in within a year of the factory date.
In the replacement window
A tank water heater (gas or electric) typically lasts 8 to 12 years, and this one is in that range. It may keep going, but this is the age to budget for a replacement rather than wait for it to fail.
How Rheem serial numbers encode the date
2 formats are in the field. Each one below shows where the date sits; the decoder tries them all.
About 2013 to today
Newer tanks put a single plant letter (A, M, Q, W and others) in front of the date, sometimes after a few product letters such as RHLN. The two digits after the plant letter are the week of the year and the next two the year: Q1115 is week 11 of 2015, in March. A five-digit production number ends the serial. Read the first pair as a week even when it is 12 or lower.
Example: Q111516703, made Mid March 2015.
Late 1970s to about 2013
Skip any letters at the start (RH, RN, RHNG, GE and so on). The next two digits are the month and the two after that the year, so 0410 means April 2010. A plant character, usually a letter, and a five- or six-digit production number follow.
Example: 0511B33657, made May 2011.
Real examples
Serial numbers whose dates we confirmed independently (from the label, the manufacturer, or two sources that agree), decoded with the rule above.
| Serial | Read as | Manufactured | Brand and source |
|---|---|---|---|
| Q111516703 | week 11, year 15 | Mid March 2015 | Rheem, forum.nachi.org |
| RHLNQ191441441 | week 19, year 14 | Early May 2014 | Rheem, forum.nachi.org |
| 0511B33657 | 05 = May, year 11 | May 2011 | GE, forum.nachi.org |
| RH 0410B03663 | 04 = April, year 10 | April 2010 | Rheem, forum.nachi.org |
| RH 0509D05896 | 05 = May, year 09 | May 2009 | Rheem, forum.nachi.org |
Where the serial is on a Rheem water heater
On the rating plate, a sticker on the side of the tank: above the gas control valve on gas models, beside the upper element cover on electric models (some Performance Platinum electrics have it near the bottom). Newer plates also print MFG. DATE next to the serial.
Use the serial number, not the model number: only the serial carries the date.
Brands that use the same date code
These brands are made by Rheem Manufacturing (Paloma) and share the serial format, so the same rule decodes them. Who makes which brand.
- GE
- Richmond
- Ruud
How long Rheem water heaters last
A tank water heater (gas or electric) typically lasts 8 to 12 years. Brand matters less than installation, maintenance and water or air conditions, so the same range applies to Rheem.
Signs it's time to plan a replacement
- It is more than 10 years old.
- Water or rust around the base, the tank seams or the pipe connections on top. A leak from the tank body itself usually means replacement.
- Rusty, brown or bad-smelling hot water.
- Rumbling, popping or cracking sounds while it heats.
- Hot water runs out sooner than it used to.
Sources and checks
Rheem's own tool can confirm a date: Rheem: How old is my water heater?.
The rules on this page come from:
- Rheem Technical Service Bulletin 1207: How to Read Rheem/Ruud/Richmond Serial Numbers (archived 2007)
- Rheem: How to locate and read your Rheem water heating serial numbers
- Building Intelligence Center: Rheem water heater age
- Rheem: Recall of Performance Platinum electric water heaters (May 26, 2016), serial ranges with date codes
- InterNACHI forum: owner's Rheem label dated March 11, 2015 with serial Q111516703
Last verified October 5, 2026 against 21 real serial numbers. See how we check. Not affiliated with Rheem.
Common questions
Can I get the age of a Rheem water heater from the model number?
No. The model number describes the unit (its series, size and efficiency). The manufacture date is in the serial number, which is printed on the same plate.
Is the decoded date when it was made or when it was installed?
When it was made. Most units are installed within a year of their factory date, but one that sat in a warehouse or was installed later can be younger in service than the date suggests.
Who makes Rheem water heaters?
Rheem's own brand. The company was founded in 1925 and builds its residential tank water heaters in Montgomery, Alabama and in Mexico.
Did your serial decode wrong, or not at all?
Send it with the brand and equipment type. Every submission is checked by hand and, once resolved, becomes a test the decoder must pass.
Email the serial number, the brand, and whether it's a water heater, furnace, AC or boiler to support@factorydate.com.
If the label prints a manufacture date, include it: that's what lets us confirm a new format. A photo of the plate helps too.