§ 05 Equipment age
How old is my A. O. Smith water heater?
The first two digits are the year and the next two digits are the week of the year it was made.
Serial diagram · A. O. Smith water heaters
Type the serial
The first two digits are the year and the next two digits are the week of the year it was made.
Manufacturer-documented format
The A. O. Smith date code
“The first two digits of the serial number are related to the manufacture year · The next two digits are related to the manufacture week”
| Serial | Made | How | From |
|---|---|---|---|
| 2037A123456 | September 2020 | A. O. Smith’s own example: “starts with 20 … The next two digits are 37 … produced between September 7 and 13, 2020.” | Printed by the manufacturer |
| 1512A123456 | March 2015 | 15 is 2015; week 12 falls in March. | Worked by casaq from the OEM table (illustrative serial) |
The rule is published on A. O. Smith’s international support site. If your rating plate prints a manufacture date, that date wins.
Lifespan
How long a water heater lasts
About 15 years on average. An average across tank water heaters, from DOE’s survival analysis of national survey data. Hard water, sediment and a failed anode shorten it; it is not a guarantee.
“DOE estimates the average product lifetime to be around 15 years for storage water heaters.”