Williams serial number with year code S: 1999
In the Williams 1984 to 2004 format the year letter S means 1999.
Serial number decoder for Williams
Type the serial from the data plate, not the model number. Nothing is sent anywhere; the tables are in this page.
Format example: 13 AD
- A Williams serial number with year code S was built in 1999 (1984 to 2004 format; source: building-center.org).
The full year-letter table
| Year code | Year(s) |
|---|---|
| A | 1984 |
| B | 1985 |
| C | 1986 |
| D | 1987 |
| E | 1988 |
| F | 1989 |
| G | 1990 |
| H | 1991 |
| J | 1992 |
| K | 1993 |
| L | 1994 |
| M | 1995 |
| N | 1996 |
| P | 1997 |
| R | 1998 |
| S | 1999 |
| T | 2000 |
| V | 2001 |
| X | 2002 |
| Y | 2003 |
| Z | 2004 |
Month letters
| Month code | Month |
|---|---|
| A | January |
| B | February |
| C | March |
| D | April |
| E | May |
| F | June |
| G | July |
| H | August |
| J | September |
| K | October |
| L | November |
| M | December |
Official lookup: the authority
Open the official Williams lookup takes serial number; returns warranty / registration lookup; URL verified live
This site is a reference built from published tables. The manufacturer's own lookup wins whenever the two disagree.
Sources
- https://www.building-center.org/williams-hvac-age/
- img: WILLIAMS-Date-of-Manufacture-Serial-Number-Style-1.jpg (transcribed)
- https://williamscomfort.com/warranty-v2-temp/official