American Water Heater Age
American Water Heater serials put the year and the week in the first four digits, so 1102… is the second week of 2011. Enter the serial from the label to see the age and remaining life.
Part of the water heater age lookup
Serial number age lookup
Where to find the serial number
The rating label is on the side of the tank, typically above the gas valve on gas models and between the element covers on electric ones. American Water Heater labels list the model (often starting with letters like G for gas or E for electric, followed by capacity and warranty codes) and a Serial No. that is normally ten digits.
Check the label for a line with a manufacture date or a short warranty or date code. When it’s present, it’s the most reliable date you’ll find.
How the date code works
| Digits | Meaning | Example (1102123456) |
|---|---|---|
| 1–2 | Year | 11 = 2011 |
| 3–4 | Week of the year | 02 = second week of January |
| 5–10 | Production sequence | not part of the date |
- Year
- Week
- Not part of the date
Worked examples
| Serial | Built |
|---|---|
| 1102123456 | January 2011 (week 2) |
| 0749654321 | December 2007 (week 49) |
| 1918111222 | May 2019 (week 18) |
| 2433123123 | August 2024 (week 33) |
Example serials are made up to show the format; they don't belong to real units.
One factory, many names
American Water Heater’s plant in Johnson City, Tennessee, has built tanks under its own name and for other brands, including Whirlpool water heaters and various retailer and private-label names. If the label anywhere mentions American Water Heater Company or Johnson City, the same year-and-week code almost certainly applies, whatever the badge on the front says. For Whirlpool-branded tanks, the Whirlpool page covers the details.
Don’t mix it up with American Standard
American Water Heater makes water heaters. American Standard is a heating and air conditioning brand closely tied to Trane. The two are unrelated, and their serial numbers work completely differently. If you’re dating a furnace or AC with an American Standard badge, use the American Standard decoder.
How long American water heaters last
| Type | Typical life |
|---|---|
| Gas tank | 8–12 years |
| Electric tank | 10–15 years |
Signs to watch for
- Hot water with a rusty tint
- Water in the drain pan or around the base
- Popping or rumbling as the burner runs
- Hot water running out sooner than it used to
- Corrosion on the fittings on top of the tank
Replacing an American tank: what to match
If your tank is near the end, these details from the rating label make the replacement straightforward:
- Fuel and capacity: natural gas, propane or electric, and the gallons (40 and 50 are most common).
- Venting type: atmospheric (vents into a chimney or B-vent by natural draft), power-vent (a fan on top, venting through PVC to the outside), or direct-vent. A replacement with the same venting type is the simplest install.
- Height and diameter: “tall” and “short” versions of the same capacity exist for closets and under stairs. Measure the space and the old tank.
- Electrical (electric tanks): voltage and element wattage, usually 240 V with 4,500 W elements.
- Code updates: current codes may require an expansion tank, seismic straps (in some regions), a drain pan, or a flammable-vapor-resistant design on gas tanks. Older installations often lack these.
What to do with your result
Under 6 years: repair, and check the warranty. American tanks are commonly sold with 6, 9 or 12-year tank coverage.
6 to 10 years: flush it, check the anode and test the relief valve.
Over 10 years: plan a replacement. Since American is part of A. O. Smith, parts and like-for-like replacements are easy to source through plumbing supply houses.
Frequently asked questions
How do I read an American Water Heater serial number?
Take the first four digits. The first two are the year and the next two are the week of the year. 1102123456 was built in week 2 of 2011, early January.
Who owns American Water Heater?
American Water Heater Company, based in Johnson City, Tennessee, is part of A. O. Smith. It also built tanks for other brands, including Whirlpool-branded water heaters.
Why doesn't my American serial number decode?
Some older American tanks used plain sequential serial numbers with no date. Those usually have a separate date code or warranty code elsewhere on the label; if not, the manufacturer can look the serial up.
Is American Water Heater the same as American Standard?
No. American Standard is an HVAC brand related to Trane. If your furnace or AC says American Standard, use our American Standard decoder instead.
Sources and accuracy
The Whirlpool / American Water Heater decoder is built from these references and cross-checked between them. Facts are restated in our own words; any mistakes are ours.
Status: being verified against real data plates. Rules last reviewed 2026-10-18; page updated 2026-10-29. Not affiliated with Whirlpool / American Water Heater. Report a wrong result.
Part of the water heater age lookup
This page covers one brand. For all water heater brands, go to the water heater age lookup.