State Water Heater Age Lookup

State serial numbers use AO Smith's encoding scheme — the manufacture date is encoded in the first characters.

Where to find the serial

• Data plate on top of the unit (most models) or side
• Installation paperwork
• Original packaging label

Decoding format

State / AO Smith serials are typically 10-12 characters:

• First 4 digits = year + week (e.g., 2245 = week 45 of 2022)
• Remaining digits = factory sequence number

Example: 2208123456 = week 8 of 2022 (February), sequence 123456.

If format is unclear

Call 1-800-365-0024 with the serial number. State support confirms manufacture date in under 5 minutes.

Cross-check against production years

Warranty implications

Warranty runs from install date if registered; from manufacture date if not. See State warranty hub.

Bottom line

First 4 digits = year/week. Call State if unclear.