Water heater age
Find your water heater’s age on the factory label.
Most brands hide the manufacture date in the serial number. Each brand uses its own code.
The factory label helps identify when the heater was made and which parts fit it. Keep a clear photo with the installation and service records.
Use the factory label
Decode the manufacture date.
Choose the printed brand and copy the serial exactly. Add the model when you have it.
What the label can prove
Get the brand, model, and serial in one photo.
Copy the brand, model and serial together. The manufacturer’s serial format provides the date, and the model helps resolve formats that repeat or vary across product lines.
Field note · Millcreek
This heater looked clean. The label still did the talking.
The factory label carries two useful identifiers: the serial number contains the production date, and the model number identifies the equipment design. Together they help locate replacement parts, warranty records and the correct manual.
How the date is coded
The serial format changes by brand.
Bradford White
The first letter gives the year code and the second gives the month. Year letters repeat every twenty years. The trailing production number helps separate older cycles: seven digits before December 2007, eight afterward. Copy the whole serial.
Rheem, Ruud, and Richmond
Many newer serial numbers begin with month and year. Some older lines use a different pattern, which is why the brand name alone is not enough.
A. O. Smith, State, and American
A common format begins with the year and production week. Older heaters can use another format, so we check the complete label before calling the date.
The pattern does not match
That means we need a clearer label or a manual check. The result stays “not verified” until the label and date rule match.
Read the evidence
Three dates.
Three different meanings.
| Date | Meaning | Where to verify it |
|---|---|---|
| Manufactured | When the unit was made, if its serial format is verified. | The factory label and the manufacturer’s serial-number guide. |
| Installed | When it was put into service, supported by an invoice or record. | The installation invoice or service record. |
| Warranty started | The date defined by the manufacturer’s warranty terms. | The manufacturer’s warranty terms and registration record. |
A model identifies an equipment family and configuration. A serial identifies the individual unit. Similar-looking model numbers may use different controls, fuels, venting or replacement parts. Copy suffixes and prefixes as printed.
Record the manufacture date, installation date and later service visits separately. For warranty questions, use the start date defined in the manufacturer’s terms and the supporting installation or registration record.
Resolve an unclear or repeated date code
Keep a clear photo of the complete label and use the serial-number rule for that manufacturer and equipment family. Some date codes repeat; use the model generation and installation records to resolve the year.
For parts or warranty approval, verify the result with the manufacturer. Keep the original label photo attached to the service record.
For example, Bradford White’s KC date code can mean March 1993 or March 2013. Use the model and production era to resolve the year.
Bradford White: serial format and date codes (page 3) ↗Where these explanations come from
Read the manufacturer and technical references behind this lesson. For service settings, open the manual for your full model number.
Common questions
Read the manufacture date and check the equipment history.
Where is the water-heater serial number?
Look for the factory label on the side of the tank or cabinet. Do not use the yellow EnergyGuide label or the installer’s service sticker.
Why is Bradford White harder to date?
The year letters repeat every twenty years. For example, KC can mean March 1993 or March 2013. Seven trailing production digits identify the older format; eight identify the newer one introduced in December 2007. The full model and dated records help when the remaining details overlap.
Is the manufacture date the installation date?
No. The heater may have sat in a warehouse before it was installed. Receipts or permit records are better when you need the exact installation date.
Hard to read?
Send the best label photo you can get.
We’ll identify the heater, verify the age when the serial allows it, and use the same label to check parts or replacement options.