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How Old Is My Rheem Air Conditioner or Furnace?

Your Rheem unit's age is encoded in its serial number. Here is exactly how to decode it or use our free tool.

Where to find the Rheem serial number

On an air conditioner or heat pump, look for the data plate on the side or rear of the outdoor unit. On a furnace, open the upper front door — the plate is inside the cabinet.

How to decode a Rheem serial number

Format: Factory letter + WWYY

1. Find the letter in the serial (factory code: F, M, G, W or N).
2. First two digits after the letter = week.
3. Next two digits = year.

Ruud is Rheem's sister brand with the identical format.

What your unit's age means

Typical lifespan for residential HVAC is 15–20 years. Under 10 years: repair with an OEM part. 10–15 years: repairs usually still win. Past 15 years: compare repair vs replacement.

R-22 warning: if your Rheem AC or heat pump was manufactured before 2010, it likely runs phased-out R-22 refrigerant.

Frequently asked questions