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How old is my Rheem furnace or AC?

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

Scan insteadWhere is the label?

Example

7351M280616735
  • 7351Product code, not part of the date
  • MPlant: M
  • 28Week: 28 (around July)
  • 06Year: 06 = 2006

Built Week 28 of 2006 (around July)

20 years, 3 months old

In replacement window. Inside the usual 15 to 25 year lifespan, so replacement could come any time. Worth budgeting for it.

What to do now

  • Get a replacement quote now, before a breakdown in the hottest or coldest week forces a rushed choice.
  • A common rule of thumb: if the repair cost times the age in years is over 5,000, replacing usually makes more sense.
  • Ask about rebates. Many utilities and states pay toward a high-efficiency replacement.
  • Some home insurers and home buyers’ inspectors ask the age of the HVAC system. Florida 4-point inspections record it.
  • Most HVAC parts warranties run 5 to 10 years and require registration within 60 to 90 days of install. Check with the installer.
How this was read
  1. Skip the first 4 characters, 7351. They are a product code.
  2. The letter M is the plant that built it.
  3. The next two digits, 28, are the week of the year.
  4. The two digits after that, 06, are the year: 2006.

Format: Rheem HVAC plant letter, week and year. Sources: CPSC 2009 Rheem and Ruud oil furnace recall (date code after the M), McGarry and Madsen: Rheem serial numbers, Building Intelligence Center: Rheem, InspectAPedia: Rheem HVAC.

Reading a Rheem serial number

Find the letter followed by four digits in the middle of the serial. Those digits are the week and the year, so M2806 means the 28th week of 2006.

Rheem water heaters use different formats. Use the water heater checker for those.

About Rheem

  • Rheem started in Emeryville, California in 1925 making steel drums. Its first Rheemaire central air conditioner came out in 1956.
  • Paloma of Nagoya, Japan has owned Rheem since 1988. Rheem moved its headquarters to Atlanta in 2007.
  • Rheem’s US air conditioning business is based at its Fort Smith, Arkansas plant, which has run for more than 50 years.

Sources: Rheem 100 Years, Rheem Invests $20 Million in Fort Smith Operations, Creates 100 Jobs

Rheem HVAC plant letter, week and year

Used about 1974 to today. Example: 7351M280616735

Find the letter that is followed by four digits and then a running number. Those four digits are the week (2 digits) and the year (2 digits). M2806 means the 28th week of 2006. Longer serials put a product code in front.

Worked example: 7351M280616735 was built Week 28 of 2006 (around July), so it is 20 years, 3 months old as of October 2026.

Sources: CPSC 2009 Rheem and Ruud oil furnace recall (date code after the M), McGarry and Madsen: Rheem serial numbers, Building Intelligence Center: Rheem, InspectAPedia: Rheem HVAC

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.

YearRecallHazard
2009Rheem and Ruud oil furnacesIf miswired, the oil burner can keep running after the blower stops and start a fire.
1999Rheem electric furnaces and air handlersHeating elements can break up and blow hot metal bits into the ducts, which can start a fire.
1998Plastic HTPV vent pipes on gas furnacesPlastic vent pipes can crack or separate and leak carbon monoxide.