The earliest American Water Heaters range in the records starts with 9332, which means production week 32 of 1993, and ends with 9712, or week 12 of 1997. A later company label shows the same YYWW format in 2000.
Serial dates from week 13 of 1997 through the end of 1999 fall between these two records. Appliage can calculate one year and week for them, but marks the age as Estimated because no official record prints a range for those intervening years.
Find the Age of Your American Water Heater with Appliage
Locate the Manufacturer Label on the Tank Jacket
The large data label is fixed to the tank jacket. A gas model commonly has it near the warning panel or gas control. On an electric model, check beside an element access panel. The label should name American Water Heater Company or American Water Heaters and include both Model No. and Serial No.
The data label is on the exterior. There is no need to remove a burner cover, gas valve, or electrical panel.
Keep Every Character When You Enter the Serial
Type the complete serial number into Appliage. A leading zero is part of the year field: 0140 begins with year 01 and week 40. The serial number alone provides the date. Enter the model number too when it is available because it helps identify whether the tank is a residential American Water Heaters model. Commercial tanks may use another serial format.
American Water Heaters Age Rules
- Digits 1–2Manufacture year
01 means 2001 - Digits 3–4Production week
40 means week 40 - Position 5 onwardTank identifier
119841 identifies the unit
The week code does not represent a calendar month or an exact day. Appliage reports the production week and calculates the estimated age from that week.
The Verified Range Starts at 9332
The lower boundary is a complete serial prefix: 93 | 32. It means production week 32 of 1993. A court approved settlement lists American Water Heater Company serial ranges beginning at this point, which gives the rule a specific week rather than only a starting year.
Lower Boundary Example: 9332000001
For example, in the serial number 9332000001, 93 means 1993, 32 means production week 32, and 000001 identifies the tank. This is the first date in the documented range. Therefore, the manufacture date is production week 32 of 1993.
| Serial date | Age result | Evidence behind the boundary |
|---|---|---|
| 1993 W32–1997 W12 | One year and week | The settlement prints this American serial range |
| 1997 W13–1999 W53 | One year and week; age marked Estimated | The period falls between the settlement range and the later maker label |
| 2000 onward | One year and week | The American label diagram identifies the first four digits as YEAR WEEK |
| Before 1993 W32 | No age | No American serial record extends the rule earlier |
Why a 1999 Serial Still Produces One Date
The settlement ends at week 12 of 1997. A later American label identifies the same YYWW positions in 2000, and a federal recall lists 2001 prefixes in that layout. These records show the same serial structure immediately before and after the 1997 to 1999 interval.
1999 Example: 9950123040
For example, the serial number 9950123040 starts with 99 | 50. The year code means 1999, and the week code means production week 50. Therefore, the manufacture date is production week 50 of 1999.
Official records show the same YYWW format before and after this serial date, but no listed record contains this exact 1999 prefix. Appliage therefore marks the age as Estimated.
Why 9331000001 Does Not Get an Age
For example, the serial number 9331000001 starts with 93 | 31, which appears to mean production week 31 of 1993. That date is one week before the first documented American boundary. The plant operated under the Mor Flo name then, and no published Mor Flo serial record connects this number to a manufacture date. Therefore, Appliage returns no age.
A week code must also fall from 01 through 53. Week 00 or a value above 53 is not a production week. Commercial water heaters can use other serial layouts, so the product description on the label should be checked before applying the residential rule.
American Water Heaters after Joining A. O. Smith
American Water Heaters was already using the YYWW format before it became part of A. O. Smith. A. O. Smith’s service guide now lists American Water Heaters under the same rule: the first two serial digits give the year, and the next two give the production week. The acquisition did not create a new date format.
The name on the rating plate still decides which guide to use. Select American Water Heaters for a tank carrying that brand. A tank whose plate says A. O. Smith belongs in the A. O. Smith water heater guide, because some older A. O. Smith tanks use month letters instead.
Sources
- A. O. Smith 2024 Service and Warranty Guide. The company guide publishes the opening year and week positions and includes American in its service program.
- Court approved dip tube settlement notice. American signed the notice, which lists serial ranges from 9332 through 9712.
- American Water Heater Company label diagram. The company’s label image prints YEAR WEEK beneath the serial number.
- CPSC recall 02-020. The federal notice identifies American units by 2001 serial prefixes.
Appliage is an independent appliance age research tool. It is not affiliated with or endorsed by American Water Heaters or A. O. Smith. See how the evidence standard works on our About page.
