Rheem furnace and AC age by serial number
Rheem furnaces, air conditioners and heat pumps record the week and year of manufacture in the serial. Current serials start with a plant letter and older ones are longer, so this Rheem serial number lookup tries each style to find the Rheem manufacture date.
Where do I find the serial number?
Rheem gas furnaces keep the rating plate inside the cabinet, on the wall of the burner or blower compartment. Outdoor Rheem units carry it on a side panel. If the label is hard to read, a phone camera with the flash on often helps.
How to read a Rheem serial number
A current Rheem heating or cooling serial is a letter followed by nine digits. The letter is the plant, the next two digits are the week, and the two after that are the year. W291013412 reads as week 29 of 2010. Older Rheem units have longer serials with a plant letter in the middle, followed by the same week and year pattern.
Plant letter, week, year, sequence
- Used
- Current style
- Format
- Plant letter, week, year, sequence
- Example
- W291013412
Example, read
Longer serial with a plant letter in the middle, then week and year
- Used
- Older style
- Format
- Longer serial with a plant letter in the middle, then week and year
- Example
- 7351 M2806 16735
Example, read
The plant letter is usually F, M, G, W or N. The four digits after it are the week, then the year.
Month, year at the start (water heater style on some older units)
- Used
- Older style
- Format
- Month, year at the start (water heater style on some older units)
- Example
- 0804B10488
Example, read
Where to find the serial number
Rheem gas furnaces keep the rating plate inside the cabinet, on the wall of the burner or blower compartment. Outdoor Rheem units carry it on a side panel. If the label is hard to read, a phone camera with the flash on often helps.
Brands with the same format
Ruud uses the same serial format as Rheem.
Questions
How old is my Rheem air conditioner?
For a serial like W311830586, skip the first letter and read the next four digits as week and year. That one is week 31 of 2018.
My Rheem serial is long with a letter in the middle. Can you read it?
Yes. Find the plant letter, usually F, M, G, W or N. The four digits after it are week then year, so CB5D302F099903346 reads as week 9 of 1999.
Why does the decoder say this format is less well documented?
The two older Rheem styles come from fewer sources than the current one. The date is read the same way, but check it against any date printed on the plate.
Are Rheem water heaters read the same way?
No. Rheem water heaters use a different format, where the first four digits are the month and year. Use the Rheem water heater page for those.
Does Ruud use the same serial format?
Yes. Ruud furnaces and air conditioners use the same serial format as Rheem.
Can I look up a Rheem model number here?
No. On Rheem heating and cooling equipment the model number shows the product type and size. The age is in the serial, which is what we read.