Rheem AC and heat pump age by serial number
Rheem air conditioners and heat pumps have carried their manufacture date in the serial number since 1974. Type yours to decode it. Or read how the code works below and do it by hand.
The same code covers Ruud, Sure Comfort and WeatherKing.
Example: Rheem air conditioner, serial 8254W141302706
Made Early April 2013
13 years, 6 months old
The serial reads as week 14 of 2013 (Mid-1970s to today (letter in the middle) format). Made, not installed: most units go in within a year of the factory date.
In the replacement window
A central air conditioner typically lasts 10 to 15 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
One format covers the units in the field. Here's where the date sits.
Mid-1970s to today (letter in the middle)
Find the last letter in the serial (usually M, F, N, W or G); the code before it identifies the product. The two digits right after that letter are the week of the year and the next two the last two digits of the year. The digits after that are the production sequence.
Example: 8254W141302706, made Early April 2013.
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 |
|---|---|---|---|
| 8254W141302706 | week 14, year 13 | Early April 2013 | Rheem, forum.nachi.org |
| 7969W471102857 | week 47, year 11 | Late November 2011 | Ruud, forum.nachi.org |
| 7653N270900726 | week 27, year 09 | Late June or early July 2009 | Ruud, forum.nachi.org |
| T M3604 09792 | week 36, year 04 | Late August or early September 2004 | Ruud, forum.nachi.org |
| 1R6670ADAAF500306364 | week 50, year 03 | Mid December 2003 | Rheem, forum.nachi.org |
Where the serial is on Rheem ACs and heat pumps
On a side panel of the outdoor unit, near the service valves and electrical box. The plate prints the manufacture month and year (MFD, MFD./FAB or MFG. DATE) beside the model number.
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 Paloma (Rheem Manufacturing Company) and share the serial format, so the same rule decodes them. Who makes which brand.
- Ruud
- Sure Comfort
- WeatherKing
How long Rheem air conditioners and heat pumps last
A central air conditioner typically lasts 10 to 15 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.
- Breakdowns are frequent, or a repair approaches half the cost of a new system.
- Energy bills keep climbing with no change in use.
- Uneven cooling or loud noises.
- It uses R-22. New R-22 hasn't been made or imported in the U.S. since 2020, so recharges rely on recovered refrigerant.
Sources and checks
Rheem's own tool can confirm a date: Rheem warranties.
The rules on this page come from:
- CPSC with Rheem: the date code is the four digits after the letter M, week first and year second
- InterNACHI forum: CPSC release 09-104, Rheem oil furnaces (date code is the four digits after an M in the middle of the serial)
- Building Intelligence Center: Rheem HVAC age (styles 2 to 4)
Last verified October 5, 2026 against 11 real serial numbers. See how we check. Not affiliated with Rheem.
Common questions
Can I get the age of a Rheem AC or heat pump 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.
Does this work for a Rheem heat pump?
Yes. Rheem heat pumps use the same serial format as its air conditioners, so the decoder reads them the same way.
Who makes Rheem air conditioners and heat pumps?
Rheem started in 1925 making steel drums, sold its first central home heating and cooling systems in 1956 and opened its air-conditioning division in Fort Smith, Arkansas, in 1970. Japan's Paloma has owned Rheem since 1988.
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.