How do you read an A.O. Smith serial number?
A.O. Smith’s service and warranty guide says the first two digits of the serial number are the year of manufacture and the second two are the week. A manufacturing year can have up to 53 weeks. The guide’s own example, 1719106145074, was built in the nineteenth week of 2017.
Source: Service and Warranty Guide for Contracted Service Providers, July 2024 (How to Read the Serial Number), checked October 19, 2026.| Digits | What they mean | In 1719106145074 |
|---|---|---|
| 1 and 2 | Year of manufacture | 17: 2017 |
| 3 and 4 | Week of manufacture (01 to 53) | 19: week 19 |
| The rest | Production number | 106145074 |
What will the home systems age report add?
The home systems age report will put your A.O. Smith water heater next to every other major system in your home, each with its build year, how long that kind of system typically lasts, and what to budget for replacing it.
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We’re building a home systems age report: your A.O. Smith water heater and every other major system, each with its age, typical life and replacement budget.
Where is the serial number on an A.O. Smith water heater?
It’s on the rating plate, a black and white label on the front of the tank on standard residential models. The plate lists the model number and the serial number, and has a QR code. Scanning the code with a phone camera shows the model, serial number and warranty status without any decoding.
What do some A.O. Smith serial numbers decode to?
The first row is A.O. Smith’s own example. The others are made up to show the rule and don’t belong to real water heaters.
| Serial | Year | Week | Built around |
|---|---|---|---|
1719106145074 (A.O. Smith’s example) |
2017 | 19 | Mid-May 2017 |
2203112345678 |
2022 | 03 | Late January 2022 |
1048298765432 |
2010 | 48 | Early December 2010 |
How long do A.O. Smith water heaters last?
A.O. Smith doesn’t publish a typical life in years. For tank water heaters in general, the U.S. Department of Energy estimates an average life of around 15 years. Any one tank can last longer or shorter than the average.
Why does the build date matter for the warranty?
A.O. Smith’s residential warranties run from the date on your bill of sale. Without one, they run from the date of manufacture shown on the rating plate, so the serial number can decide whether a tank is still covered.
Common questions about A.O. Smith water heater serial numbers
My A.O. Smith serial starts with letters. How do I read it?
Older A.O. Smith water heaters used serials that start with letters, and A.O. Smith doesn’t publish how to read them. Scan the QR code on the rating plate, or call A.O. Smith with the model and serial number, and they can tell you the build date.
How do I turn the week into a month?
Multiply the week by seven to get a rough day of the year. Week 19 is around day 133, in mid-May. A.O. Smith doesn’t say how it numbers weeks, so treat the month as approximate.
Is the build date the same as the install date?
Not always. A water heater can sit in a warehouse for weeks or months before it’s installed. If you have the installer’s invoice, that date is the one the warranty uses.