A.O. Smith Logo

About A.O. Smith

The company was founded in 1874 in Milwaukee, Wisconsin, where today the Company is headquartered. A. O. Smith employs over 12,000 individuals at operations in the United States, Canada, Mexico, China, India, the United Kingdom and the Netherlands. We also have sales and distribution in more than 60 countries around the world.

Click to scroll to A.O. Smith contact information
HVAC Age / Serial Decoder

Style 1

The first two numbers represent the year the heater was built. If your heater was built before 2008, the next two numbers represent the month. If your heater was built after 2008, the next two numbers represent the week.

Variant A
Example Serial Number
2 2 1 3 A 1 2 3 4 5 6
This would read as 13th Week of 2022. Grey is ignored.

Year is Green, Week is Blue.

Variant B
Example Serial Number
S 2 2 1 3 F 1 2 3 4 5 6
This would read as 13th Week of 2022. Grey is ignored.

Year is Green, Week is Blue.

Variant C
Example Serial Number
2 2 1 3 1 2 8 9 1 4 1 7 7
This would read as 13th Week of 2022. Grey is ignored.

Year is Green, Week is Blue.

Style 2

Ignoring the first letter, the second letter represents the month, and the first two digits represent the year. The difference between Variant A and Variant B is the introduction of hyphens and overall length in Variant B.

Variant A
Example Serial Number
M B 0 3 A 1 2 3 4 5 6
This would read as February, 2003. Grey is ignored.

Year is Green, Month is Yellow.

Variant B
Example Serial Number
M B 0 3 - 1 2 3 4 5 6 7 - S 1 2
This would read as February, 2003. Grey is ignored.

Year is Green, Week is Yellow.

How to translate Character to Month
A January
B February
C March
D April
E May
F June
G July
H August
J September
K October
L November
M December

Style 3

The first letter represents the month, and the first two digits represent the year. The difference between Variant A and Variant B is the introduction of hyphens and overall length in Variant B.

Variant A
Example Serial Number
A 0 3 A 1 2 3 4 5 6
This would read as January, 2003. Grey is ignored.

Year is Green, Month is Yellow.

How to translate Character to Month
A January
B February
C March
D April
E May
F June
G July
H August
J September
K October
L November
M December
Contact Information for A.O. Smith
Phone Numbers

Tech Support and Warranties
(800) 527-1953
Replacement parts
(800) 821-2017

Email Addresses

Tech Support and Warranties
help@hotwater.com
Replacement Parts
contactus@hotwater.com

Websites

A.O. Smith Website
A.O. Smith - Brands

Addresses
A. O. Smith Corporate Headquarters
11270 West Park Place, Suite 170
P. O. Box 245008
Milwaukee, Wisconsin 53224
USA
Important Note: All trademarks belong to their respective owner(s). No ownership is implied by Inspector Handbook. Inspector Handbook is a data aggregate that utilizes manufacturer and third party data to compile the information presented. Inspector Handbook or it's affiliates do not claim ownership of any trademarked materials.