HVAC and water heater date codes by maker
Rheem, Bradford White, A. O. Smith and Goodman each put the build date in the first characters of the serial number.
| Maker | Rule in one line |
|---|---|
| Rheem (water heaters) | Digits 1–2 month, 3–4 year |
| Bradford White | Letter 1 year (two possible years), letter 2 month |
| A. O. Smith | Digits 1–2 year, 3–4 month or week |
| Goodman and Amana | Digits 1–4 YYMM |
| Maker | Maker's example | Maker's reading |
|---|---|---|
| Rheem | 1209D01234 | Month 12, year 09 |
| Bradford White | JK… | October 2012 or 2032 |
| A. O. Smith | U0106413635 | June 2001 |
| Goodman and Amana | 2301… | January 2023 |