Where to find the serial number
- On the outdoor unit (the condenser): a metal or sticker label on the side panel, often near the electrical connections.
- The indoor unit (air handler) has its own label, usually on the side panel. It can be a different age from the outdoor unit.
- Mini-splits: on the side of the outdoor unit, or under the front cover of the indoor head.
- Take a photo and zoom in if the label is faded. If it prints the manufacture date, that date wins.
How to read the serial number, brand by brand
Carrier, Bryant, Payne or Day & Night
The first two digits are the week and the next two are the year: 4006A17330 was made in week 40 of 2006.
Trane or American Standard
Since 2010 the first two digits are the year and the next two the week. From 2002 to 2009 the first digit is the year (91531S41F = 2009).
Lennox
Skip the first two digits (the plant). The next two are the year and the letter after is the month: 1606B13871 is February 2006.
Goodman, Amana or Daikin
The first two digits are the year and the next two the month: 1609... is September 2016.
Rheem or Ruud
Find the plant letter (F, G, M, N or W). The two digits after it are the week and the next two the year: W2910 is week 29 of 2010.
York, Coleman or Luxaire
Newer serials: the 2nd and 4th characters together are the year and the 3rd is the month (K is September). W0K5 is September 2005.
Heil, Tempstar, Comfortmaker, Arcoaire or KeepRite
Skip the first letter. The next two digits are the year and the two after are the week.
Mitsubishi (mini-split)
The first digit is the last digit of the year and the second is the month (X, Y, Z are October to December).
Fujitsu (mini-split)
Fujitsu serials don't include the date; the label or Fujitsu's support line will have it.
How long they last in Florida
| Type | Typical life |
|---|---|
| Central AC systems | 10 to 15 years |
| Heat pumps | 10 to 15 years |
| Mini-splits | 12 to 20 years |
Florida AC runs most of the year, so systems tend toward the low end of national ranges. Homes near the coast see salt air shorten that further unless the coils are protected.
Common questions
How long does an AC last in Florida?
Most central AC systems and heat pumps last about 10 to 15 years in Florida. Near the coast, salt air can shorten that.
Should I replace my AC before it fails?
If it's past about 12 years, needs repairs most summers, or still uses R-22 refrigerant, a planned replacement usually costs less than an emergency one in August.
My outdoor and indoor units have different years. Which counts?
Both matter. They're designed to work as a matched pair, so if one is much older, replacing them together is usually the better long-term choice.
Does an old AC affect my insurance?
Florida insurers may ask the AC's age and condition on a 4-point inspection. Our 4-point inspection check shows what they may ask about your home.
What if my brand isn't listed?
Many brands are made by the same few companies. Send us a photo of the label and we'll read it for you.
Sources
Building-Center.org HVAC age guides · PickHVAC serial number guides · InterNACHI life expectancy chart · HVAC.com: how long ACs last in Florida. Formats can vary on very old or unusual units; the date printed on the label always wins.