Comfortmaker furnace and AC age by serial number
Comfortmaker serial numbers carry the year and the week of manufacture, usually right after a plant letter. Type the serial from your furnace or air conditioner into this Comfortmaker serial number lookup to read the Comfortmaker manufacture date.
Where do I find the serial number?
The Comfortmaker rating plate is inside the furnace, on the cabinet wall once the front panels are off. On outdoor equipment, it is on the outside of the cabinet near the electrical box.
How to read a Comfortmaker serial number
A typical Comfortmaker serial is one letter and nine digits, like E072514528. E is the plant, 07 is the year and 25 is the week, so it reads as week 25 of 2007. R883512345 follows the same pattern and reads as week 35 of 1988.
Plant letter, year, week, sequence
- Used
- 1980s to present
- Format
- Plant letter, year, week, sequence
- Example
- E072514528
Example, read
Year, week, letter, sequence
- Used
- 1990s onward
- Format
- Year, week, letter, sequence
- Example
- 9845B12345
Example, read
Only one source documents this format. It has the same shape as the week-first format, so we try both readings and show every one that fits.
Week, year, letter, sequence (Carrier style)
- Used
- 2006 onward on some lines
- Format
- Week, year, letter, sequence (Carrier style)
- Example
- 2806A12345
Example, read
Reported on some Day & Night units from 2006 on.
Where to find the serial number
The Comfortmaker rating plate is inside the furnace, on the cabinet wall once the front panels are off. On outdoor equipment, it is on the outside of the cabinet near the electrical box.
Brands with the same format
Heil, Tempstar and Day & Night use the same serial format as Comfortmaker.
Questions
How old is my Comfortmaker furnace?
Read the second and third characters as the year. The fourth and fifth are the week.
Can a Comfortmaker serial be read two ways?
Yes, if it starts with four digits and a letter. Then it can mean year and week or week and year, and we show every valid reading.
Does Comfortmaker use the same serial format as Heil and Tempstar?
Yes. Comfortmaker uses the same serial format as Heil, Tempstar and Day & Night.
Why won't my Comfortmaker serial decode?
Check the number of characters and that each zero is not the letter O. Formats used before 1980 are not covered.
How close is a week to a real date?
Within a week. We say early, mid or late in the month so the answer reads like a normal date.
Can I look up a Comfortmaker model number here?
Not here. A Comfortmaker model number describes the product and its size, and the build date is only in the serial.