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Official A O Smith warranty & serial services

Read the plate. Check the evidence.

A.O. Smith Water Heater Serial Number Lookup & Age

Find supported A.O. Smith water-heater date codes, older brand-label context and the separate model number needed for manuals. Confirm the manufacturer and serial system before decoding.

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Check a documented system

What’s on the rating plate?

Water heaters; not A. O. Smith electric motors.

Spaces and dashes are accepted. Check O/0 and I/1, and keep any leading zeros.

Checks ENERGY STAR model records and searches manuals separately from the serial. Certification records do not establish this unit’s manufacture date.

Confirm your equipment and numbering system

For a historical or shared water-heater label, choose the documented system only after confirming the tank manufacturer and model family. Choose a system only when it matches the product family and its documentation. A purchase year or a manual’s publication date does not establish a manufacturing date.

Explore a sourced example:

Choose the equipment family

A.O. Smith serial numbers by device type

Match the product, manufacturer and documented serial layout before interpreting a date. The model is a separate label field; a date code alone does not identify capacity, installation date or warranty entitlement.

Scope matters

Supported formats
and historical limits.

  • Manufacture date is distinct from installation, purchase and warranty start dates.
  • The date code does not identify a full model, capacity or configuration. Enter the separate model from the rating plate for manual search.
  • Older pre-2004 AOS letter/number and tankless OEM formats require their own verified guides. No universal model extraction is supported.
  • A bare nine-digit SAP barcode serial contains no date; copy the separate four-digit YYWW prefix or BUILD DATE.

Research reviewed October 16, 2026. This independent tool applies published rules and retains unresolved years and model candidates.

Source references

Water heaters: year and production week

water-heater

YYWW: first two digits year; next two production week. The 2024 manufacturer guide permits week 53. No model, capacity, fuel or installation date is encoded by these four digits. 2008 is a conservative supported-range limit, not an asserted universal changeover. The October2016 SAP change uses a13-character printed date-plus-serial. A bare nine-digit barcode/SAP serial has NO date code and is deliberately not decoded.

Water heaters: letter month and year, 2004-2007

water-heater

Manufacturer/CPSC notices document the A-L/M month series with I omitted: L07 is November 2007; M07 December 2007. This rule is intentionally limited to the observed 2004-2007 family.

Water heaters: plant and month letters, early 2004

water-heater

The January-June 2004 recall serial-prefix table includes a leading plant character before the month. Do not strip an arbitrary leading letter from every later serial.

Historical A. O. Smith supplied-chart leading-code/month/year

Only the supplied anonymized old *H 06******shape, with confirmed historical water-heater family.

The 2010 secondary chart gives August 2006 but no full unit serial. This narrow ten-character proposal mirrors its anonymized illustration; the asterisks do not prove every real factory suffix. Existing independently reviewed 11-character A. O. Smith/State rules remain unchanged. Month Nis not invented from the chart’s erroneous A-through-Ndescription.

Select only after confirming the water heater or boiler family and numbering system described here. Brand ownership alone does not establish this system.

A. O. Smith International BFC/EES/COF: 15-digit year/week serial

A. O. Smith International water heaters using the 15-digit numeric example in the BFC/EES/COF UK parts documentation; excludes US bare 9-digit SAP and 13-character date-plus-serial labels.

Official international guidance explicitly states first two digits year and next two production week. International parts documents print 123707002601001 with year/week annotations; this15-digit form is outside the existing North-American11/13-character regex. The trailing 11 digits remain opaque; do not infer a consumer model, production plant or warranty.2012 is a conservative example-backed implementation floor, not a manufacturer-declared format introduction.

Confirm A. O. Smith International water-heater documentation uses this15-digit YYWW numbering scheme, such as the BFC/EES/COF UK parts lists. Do not select for a US 9-digit SAP barcode or infer region merely from serial length.

Reading your result

A O Smith lookup questions

Why does the year code match more than one year?

Some systems reuse letters or only encode the last one or two year digits. Every supported interpretation is retained. A decade supplied from reliable records can narrow the reading; the tool does not automatically pick the newest year.

Does the serial identify my exact model?

Usually the model is a separate plate field. Where published serial ranges actually identify a model, the result shows model candidates and links to their manuals. Overlapping ranges remain ambiguous.

Can I share the result?

After a lookup, the address includes the serial in a fragment beginning with #serial=. Use “Copy share link” to share the serial and selected context. Opening the link runs the same lookup. The fragment is not a query-string result page.