Carrier furnace and AC age by serial number
Carrier furnaces, air conditioners and heat pumps built since about 1980 carry a ten-character serial that opens with the week and year of manufacture. Type yours into this Carrier serial number lookup and we will read the date from the first four digits.
Where do I find the serial number?
On a Carrier gas furnace, open the front door and look on the side wall of the cabinet for the rating plate. On the outdoor condenser or heat pump, the plate is usually on a side panel near the refrigerant and electrical connections. An indoor coil can carry its own plate with a separate serial.
How to read a Carrier serial number
A Carrier serial from about 1980 on has ten characters: four digits, a letter, then five digits. The first two digits are the week of the year and the next two are the year. The letter marks the plant and the last five digits are a sequence number.
- Used
- About 1980 to present
- Format
- Week, year, plant letter, sequence
- Example
- 4006A17330
Example, read
Check the brand first
A Lennox serial has the same shape but means something different: there the third and fourth digits are the year. Always decode with the brand printed on the unit.
Units made before about 1980 used letter-coded formats that we do not decode yet.
Where to find the serial number
On a Carrier gas furnace, open the front door and look on the side wall of the cabinet for the rating plate. On the outdoor condenser or heat pump, the plate is usually on a side panel near the refrigerant and electrical connections. An indoor coil can carry its own plate with a separate serial.
Brands with the same format
Questions
How old is my Carrier furnace or AC?
Read the first four digits of the serial. In 4006A17330, the 40 is the week and the 06 is the year, so it reads as week 40 of 2006.
Why does the decoder ask for the brand?
A Lennox serial has exactly the same shape as a Carrier one, but Lennox puts the year in a different place. The same ten characters would give a different date, so the brand you pick decides how the serial is read.
My Carrier serial starts with letters. Can you read it?
Units built before about 1980 used letter-coded formats that this site does not decode yet. The rating plate may also show a separate manufacture date.
What does a week number mean in months?
Week 1 falls in early January and week 52 in late December. We turn the week into a rough part of the month, such as early October, so you get a plain date.
Is the Carrier manufacture date the same as the install date?
Not always. The serial tells you when the unit left the factory. Installation can follow weeks or months later, and the installer's paperwork will show the exact day.
Can I look up a Carrier model number here?
No, this site only dates equipment from the serial. The Carrier model number tells you the type of unit and its size, which is what a technician needs for parts.