State water heater age by serial number
State water heaters built since 2008 carry the year and week of manufacture in the first four digits, and older serials start with a month letter. This State serial number lookup reads either style to give the State manufacture date and the heater's age.
Where do I find the serial number?
The State rating label is on the outside of the tank jacket, typically in the upper half or just above the burner access. On a gas unit, look near the gas control. On an electric unit, look near the upper element panel.
How to read a State serial number
A current State serial opens with the year in two digits and the week in two more, so 0912A123456 reads as week 12 of 2009. Pre-2008 units begin with a single month letter followed by a two-digit year: C051234567 reads as March 2005.
Year, week, then sequence
- Used
- 2008 to present
- Format
- Year, week, then sequence
- Example
- 1210A002243
Example, read
Month letter, two-digit year, sequence
- Used
- Before 2008
- Format
- Month letter, two-digit year, sequence
- Example
- C051234567
- Months
- A to M, with I skipped. J is September, M is December.
Example, read
The month letters for September to December are less certain than those for January to August.
Where to find the serial number
The State rating label is on the outside of the tank jacket, typically in the upper half or just above the burner access. On a gas unit, look near the gas control. On an electric unit, look near the upper element panel.
Brands with the same format
A. O. Smith uses the same serial format as State for the year, week, then sequence format (2008 to present).
Questions
How old is my State water heater?
Look at the first character. A digit means year then week. A letter means the older style, where the letter is the month and the next two digits are the year.
What month is the letter C on an older State serial?
C is March. A to H stand for January to August, and we read J to M as September to December.
Why does the decoder call some State months less certain?
The sources describe the September to December letters inconsistently, so we flag those four months. January to August are well documented.
Is a State serial read like an A. O. Smith one?
For 2008 and later, yes. The older formats differ: A. O. Smith adds a plant letter before the month letter.
Can a State serial be from before 1960?
Not in the formats we decode. For the older month-letter style we accept years from 1960 to 2008.
Can I look up a State model number here?
No. State model numbers tell you the heater type and capacity. Only the serial number shows when it was built.