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Water heaters date-code guide

American Water Heater serial number lookup

American Water Heater products commonly use A. O. Smith-family date codes with the year and production week near the front.

Parent
A. O. Smith Corporation
Common code
A widely used style begins with two digits for year and two digits for production week (YYWW).
Reviewed
August 8, 2026

Instant equipment lookup

Decode the manufacturing date

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Equipment type

Using A widely used style begins with two digits for year and two digits for production week (YYWW).

Type exactly what is printed. Spaces and dashes are ignored.

Optional: add model number for capacity cluesAdd model

Model decoding is labeled as a clue unless the exact format is documented.

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EQUIPMENT DATA
MODEL24ABC636A003
SERIAL5019X30312
WeekYear

See exactly how the code was read

SerialAtlas highlights the date characters, names the matching rule, and shows alternative interpretations when the code is ambiguous.

  • Current age calculated automatically
  • Confidence and rule source shown
  • Optional model-capacity clue

Evidence-led route update

American Water Heater date-code evidence

If you need to estimate an American Water Heater’s manufacture age, read the year-and-week prefix from the serial on its rating plate.

Use A. O. Smith evidence for the American Water label

A widely used style begins with two digits for year and two digits for production week (YYWW). American Water Heater is represented by the A. O. Smith family’s verified YYWW format. The parent-family relationship is useful context for the date read, while the exact product still controls support. American Water Heater is represented by the A. O. Smith family’s verified YYWW read. Keep the American Water label, model, capacity, and fuel or power fields together so the family relationship does not erase product-specific support context.

Worked example: 0950A12345

0950A12345 — The verified decoder reads this fixture as Week 50 of 2009. The date is a manufacture estimate, not an installation date.

When an American Water ProLine question needs support

An age estimate cannot answer a ProLine parts, registration, or coverage question. Use the full model and serial with official A. O. Smith support when the product is commercial or specialty.

Model number vs. serial number

The American Water model identifies the product family and the serial supplies year/week evidence; both are needed for support. Keep model, serial, capacity, and fuel or power information together when checking a ProLine or other product-family question.

Limits and official support

Commercial and specialty A. O. Smith-family products require confirmation from the full rating plate. If the result affects warranty, registration, parts, safety, or replacement decisions, use the complete model and serial with the manufacturer or a qualified professional. SerialAtlas is an independent reference, not an official warranty lookup or warranty coverage decision.

Open American Water Heater support route

How to read a American Water Heater serial number

A widely used style begins with two digits for year and two digits for production week (YYWW). SerialAtlas removes spacing and punctuation, then applies only the documented rule families mapped to American Water Heater. The lookup remains in the browser.

Try this documented-style example0950A12345Load example

Equipment covered

  • gas tank water heaters
  • electric tank water heaters
  • heat-pump water heaters
  • selected commercial units

Commercial, imported, very old, specialty, and private-label equipment can use a different code. Confirm the full rating plate before accepting a result.

Where to find the rating plate

  • Upper or lower side of the tank jacket
  • Near the gas control valve on gas models
  • Behind an electrical access panel
  • Side or bottom edge of a tankless cabinet

Why more than one date can appear

Two-digit years and repeating letter cycles can point to more than one era. SerialAtlas ranks the plausible dates but keeps materially different alternatives visible. Label design, refrigerant, installation records, and product literature can resolve the era.

Source and verification

Inspector Handbook open reference data (CC BY 4.0). Independently implemented and reviewed August 8, 2026.

Open reference source

What this result does not prove

A manufacture date is not an installation date, warranty decision, recall match, condition assessment, or replacement recommendation. Confirm high-stakes decisions with the manufacturer or a qualified professional.