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A.O. Smith / State water heaters

How old is my State water heater?

Enter the serial number from the label. The date comes from State's documented serial rules, not a guess.

Look for “Serial No.” or “S/N” on the label. Spaces and dashes are fine.

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How to read a State water heater serial number

State water heaters are decoded with the same rules as A.O. Smith, and the official evidence names State directly: CPSC recalls from 2005 and 2019 list State among the affected brands and print the date codes. Since about 2008 the first four digits are the year and week. Before that, State serials often start with a month letter and a two-digit year, so a serial beginning G04 was made in July 2004.

  • Year + week (2008 onward)

    Example: 1210A002243 (A.O. Smith) was made in March 2012. For heaters built since about 2008, the first four digits are the year and week of production: "12" is 2012 and "10" is week 10.

  • Factory letter + month letter + 2-digit year (about 1991–2007)

    Example: AF04A093001 (A.O. Smith) was made in June 2004. On older A.O. Smith and State heaters the first letter is the factory code, the second letter is the month ("F" = June) and the next two digits are the year (2004).

Not decoded yet: Pre-2008 all-numeric serials (A.O. Smith Canada), 1970s formats and tankless models are not decoded yet.

Where to find the serial number

The rating label is on the side of the tank: near the gas control valve on gas models, or above the upper heating-element cover on electric models.

State water heater model numbers

If the brand name isn't visible on the label, the model number can help. Model numbers like these follow State's published nomenclature:

How long does a water heater last?

A typical water heater lasts about 8–12 years. That's a general estimate: maintenance, usage, climate and installation all matter, and age alone doesn't tell you a unit's condition.

Range from A. O. Smith: when to repair or replace a water heater and Lennox: when to replace a water heater.

State water heater recalls

From the U.S. Consumer Product Safety Commission, checked 2026-09-29. A decoded result checks your model number against recalls live.

Questions

What does a State serial starting with 1631 mean?
16 is the year and 31 the week: week 31 of 2016. A 2019 recall that covered State heaters read the serial the same way, with first four digits from 1115 to 1631 on units made from April 8, 2011 through August 1, 2016.
How can a State serial starting with J be September?
The month letters run from A to M and skip I, so J is the ninth letter used. The 2005 recall table lists J04 as September 2004.
Why doesn’t my State model number match the A.O. Smith one?
The two brands number the same heater differently. In the U.S. DOE certification database, for example, State’s GS6-30-OCT is listed under A.O. Smith’s GCR-30 basic model. The serial date rules are the same for both brands.
How can I tell how old my State water heater is?
Find the serial number on the rating plate and enter it above. State water heaters use the A.O. Smith / State water heaters serial format, which includes the manufacture date. For example, 1210A002243 was made in March 2012: For heaters built since about 2008, the first four digits are the year and week of production: "12" is 2012 and "10" is week 10.
Where is the serial number on a State water heater?
The rating label is on the side of the tank: near the gas control valve on gas models, or above the upper heating-element cover on electric models.
How long does a water heater usually last?
A typical service life is about 8–12 years. That's a general estimate: maintenance, usage, climate and installation all matter, and age alone doesn't tell you a unit's condition.
Do A.O. Smith water heaters use the same serial format?
Yes. State and A.O. Smith use the same serial-number conventions (A.O. Smith / State water heaters), so the same decoding rules apply.
How reliable is the result?
The A.O. Smith / State water heaters rules come from documented sources, but they're in Beta while we check more real-world examples, so results are capped at medium confidence. If a serial doesn't match a documented format, we say so instead of guessing.

Same serial format: A.O. Smith water heater

Sources

Rules last reviewed 2026-09-28. These rules are in Beta while we verify more real-world examples, so results are capped at medium confidence.

Manufacture dates are decoded from manufacturer serial-number conventions and available documentation. Serial formats can change. Verify critical equipment information with the manufacturer when necessary.