How Old Is My Carrier Furnace or AC? Serial Decoder

How Old Is My
Carrier Furnace or AC?

How do I read a Carrier serial number?

Carrier, Bryant, Payne and Day & Night serials put the build date in the first four digits: week, then year. 4006A17330 was built in week 40 of 2006, around early October. The fifth character is a letter for the plant, then five more digits. Enter yours below for the age.

By Jason Strauss, founder of Answer3 · Updated October 20, 2026

Carrier Serial Number Decoder

How to Read the Serial Number

Find the data plate: inside the furnace's front panel, or on the side of the outdoor unit.

Copy the serial, a ten-character code like 4006A17330.

Digits 1–2 are the week (01–53) and digits 3–4 are the year.

The letter after them is the factory, then a five-digit sequence number.

Serial	Built
4006A17330	Week 40 of 2006 (early October 2006)
3019A30814	Week 30 of 2019 (late July 2019)

Some Carrier-family units built by ICP (Heil, Tempstar, Comfortmaker, Arcoaire) start with a letter instead of four digits. That's a different code, so this decoder won't read it; check the plate for a printed date. Very old Carrier units also used an older format.

Codes based on a week number give the month only approximately. If the plate prints a manufacture date (often labeled MFG or MFD), trust that over the serial.

How Long Does It Last?

Equipment	Typical service life
Gas furnace	15–25 years
Central air conditioner	7–15 years
Heat pump	10–15 years

Age doesn't mean a unit has to be replaced; it tells you when to start planning. A replacement you schedule costs less than one you buy the night it fails. If it's near the end of its range, write down the model, serial and capacity now, so a contractor can quote the right replacement without a trip just to read the plate.

Skip the decoding

Scan the nameplate and Answer3 Vault reads the serial, works out the age, saves the model and the maker's parts list, and reminds you before the unit reaches the end of its life.

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Carrier Age FAQ

Where is the serial number on a Carrier furnace?

On the data plate inside the front access panel, usually on the blower door or the side wall of the cabinet. Turn off the furnace's service switch before removing the panel.

Is the Carrier date the install date?

No. It's when the unit was built. Equipment often sits at a distributor for months before it's installed, so the install date is usually later.

Do Bryant and Payne use the same code?

Yes. Bryant, Payne and Day & Night are Carrier brands and use the same week-then-year serial format.

How Old Is My Carrier Furnace or AC?