Need help on Carrier Gas Furnace Age Please

Serial number 0882994 (I thought the first 4 digits were the week/year?)

Model number: 58ED050130CA
MANUF. NO.: 3587018826

House date: 1989.

Thanks folks. This one stumped me.

You’re right–the first four numbers are the week and year. The unit may well have laid around in a warehouse for 6 or 7 years before it was installed.
The house may have been started 2 0r 3 years before its finish date and the unit could have been there for some time.
So long as the unit wasn’t mfg’d after the house was built…

Thanks Jae.

Carrier can be confusing in the 1980s, so I’ll disagree.

I believe the first digit is the letter “O,” which would make the manufacture date February 1988.

If the first “digit” of 0882994 is really O, then the date would be week 88 (which makes no sense) of 1929 wouldn’t it?


During that time period, they used N = January, O = February, etc., so it’s February 1988. The 2994 is the consecutive manufacturing number.

The older Carrier serial numbers can be confusing. A while back Carrier switched from a letter + 2 digit year coding, to the current 2-digit week + 2-digit year. I thought that started in 1990, but I have also heard that started sometime in the 1980’s. However my understanding is that for the older units/coding Carrier didn’t use the letter “O” (or the letter “I”) in the serial number coding, due to possible confusion over if it’s a letter or number.

I guess it’s also possible that it’s Week 08 of 1982 (0882xxx) and that older/used equipment was used. Probably the best thing to do is call Carrier. And let us know what the outcome is because I am curious if they actually did use the letter “O”.

According to my research, they did, indeed, use the letter O. Now why in the hec they used the system they did (N = January, O = February, etc.) is beyond me. Perhaps because everyone else was using A = January, B = February, etc.?

Unfortunately, many companies have done away with the convention of not using the letters I and O. However, if you look real hard at other stampings on the manufacturer’s plate, one can usually differentiate between letters and numbers, although I have confused G with 6, S with 5, B with 8, 3 with 8, and Z with 2, as well. Darn margaritas :margarit: .

Joe, I don’t believe Carrier used the letter ‘O’ in their serial numbers during the 1980’s. The sequence was ‘N’ = January, ‘P’ = February, ‘Q’ = March, etc. Could you have mistaken the ‘Q’ for an ‘O’? If the serial number is Q882994 then the date of manufacture is March 1988. I could be wrong but this seems the most likely answer. :cool:

Q88xxxx indicating March 1998 would seem to make more sense given the circumstances, if it’s possible the first character was indeed “Q”

My understanding of the Carrier S/N coding is as follows:

For 1969 and earlier equipment they used a seven-digit S/N that was like egyptian hieroglyphics trying to figure out. So starting in 1970 they switched to a seven-character S/N, with a letter followed by six digits. For 1970 thru 1979 they used letters ‘A’ thru ‘M’ for the month (Jan-Dec, without the letter ‘I’) followed by a 2-digit year. For 1980 thru 1989 they supposedly used ‘N’ thru ‘Z’ for the month (Jan-Dec, without the letter ‘O’) followed by a 2-digit year. I guess they were originally thinking they would start over with ‘A’ thru ‘M’ starting in 1990 (who cares about units over 20 years old … lol), and then thought twice about that, and switched to the present ten-character S/N with the first four numbers indicating the week-year of production.

I have heard that Carrier switched to the current ten-character S/N earlier than 1990 (some say mid to late 1980’s), but I have never gotten a straight answer from Carrier … and they just say to call if there is any issue.

Yea, I’ve never found Carrier to be very helpful. If we could get a definitive answer, then I could change my research relating to O = February.

I just got an email reply from Carrier that they indeed didn’t use the letters ‘I’ or ‘O’ in the S/N coding for older units.

Cool. They responded. Yahoo!!!

P.S. There was a typo is my previous posts I couldn’t edit. The older Carrier S/N had a letter followed by a single digit for the year … and not a 2-digit year (which is why you need the letter to figure out the year) … :wink: