Rheem age lookup
How to read a Rheem water heater serial number
Type the serial number from the label and the decoder shows when your Rheem water heater was made. Below that: every Rheem format the decoder knows, and a real label from one of my inspections.
Accuracy is not guaranteed.
This decoder gives an estimate based on how brands have coded serial numbers in the past. Manufacturers change their formats, and a serial can be misread, so the results may be wrong. Use them as a starting point only. Confirm with the date printed on the plate or with the manufacturer.
Reading a Rheem water heater serial number
Rheem water heater serials start with a few letters you can skip. On units made before about 2012, the next four digits are the month and then the year, so 0710 means July 2010. Newer Rheem tanks use a factory letter, then the week and the year: M1818 means week 18 of 2018. Ruud and Richmond serials read the same way.
Most Rheem labels I photograph also print the date, marked MFG. DATE, on the same line as the serial, like the one above. Rheem also makes furnaces and air conditioners, and those serials read differently, so make sure the label is on the water heater.
Rheem serial number formats
Each format below has a made-up example split into its parts, so you can match it to your own serial.
Up to 4 letters, then 4 digits for the month and year (before about 2012)
ExampleRH0710N54321: Prefix RH, Month 07, Year 10, Unit number N54321.
Reads as July 2010. Used from 1980 to 2012.
- Ignore the letters at the start. The first 2 digits are the month and the next 2 are the year.
- Many plates also print a manufacture date near the serial number.
Letters ending in a factory letter, then 4 digits for the week and year (about 2010 and later)
ExampleRHM221912345: Prefix RH, Factory M, Week 22, Year 19, Unit number 12345.
Reads as week 22 of 2019. Used from 2010 to today.
- The letter right before the digits is the factory. The first 2 digits after it are the week and the next 2 are the year.
- Many plates also print a manufacture date near the serial number.
16 characters: a letter, 4 digits for the month and year, a letter, 9 digits and a letter
ExampleK0316B123456789C: Prefix K, Month 03, Year 16, Unit number B123456789C.
Reads as March 2016. Used from 1995 to today.
Most Rheem plates also print the manufacture date near the serial number. If yours does, use that date.
Where to find the serial number on a Rheem water heater
Look for a label marked Serial, Serial No. or S/N. The model number is usually right next to it, so check which one you're reading.
- Gas or electric tank. A rating label on the side of the tank, usually at eye level or above the gas control. If the tank sits in a closet, it may face the wall; a phone camera held at an angle often reaches it.
- Heat pump water heater. A label on the side of the unit, often near the top.
Brands that use the same formats
These brands share at least one serial number format with Rheem, so their serials read the same way.
Buying a home in the Portland area?
A home inspection covers the water heater along with the rest of the house, including its approximate age and visible condition. Serving the Portland metro and Southwest Washington, seven days a week.