I have a York furnace with a serial number of W0E6387257. I thought that the third letter was supposed to be the date, but as you can see there is no third letter.
If you have three or four letters at the beginning, the third letter is the year.
If you only have two letters, you won’t find the letter “O” or the number “0” in use. However, if you have three or four letters, then the first or second letter, even if it looks like the number “0,” is the letter “O.”
Thus, in your serial number, you have WOE–the letter “O,” not the number “0.” That gives you your three letters, so the third letter is the year, which is either 1975 or 1996, pick one.
The more I thought about it, the more these units look too new. I called York and they have now started using the 4th character in the serial number, which is a number. In this case it is the number 6, thus making the unit a 2006. York says they don’t use the letter O in their numbers. Just thought I would pass it along for anyones information.
Did they say when the started that? That would be useful information.
Another question would be what makes it a 2006 and not a 1996?
Nonetheless, we know that at least since 2006 they are using the fourth digit. Everything prior to 2006 in my research will remain as stated in my previous post.
I also wonder if the E is for the month of May or if the 38 is for the week of the year.