How do I know the age of my water heater?

You can determine how old your residential water heater is by looking at and decoding data on the water heater’s label.

tucson-water-heater-labelFirst, locate the manufacturers label with the serial number on the side of your unit. This sticker is usually around any warning labels and the energy guide. Check to see if the installation date is noted on the sticker. If not, then write down your serial number as it usually indicates the year and month of manufacture of the water heater. Each manufacturer uses different formats and you need to de-code the water heater serial number. Read below how to determine the age of your unit.

Rheem or Ruud

ex. 1209D1234 (MMYYPnnnn) = December 2009

MM = month of manufacture
YY = year of manufacture
P = plant identifying code
nnnn = a consecutive serial number for your individual unit

AO Smith and American

ex. 9705123445 (YYWWxxxxxx) = 1997, 5th week (early February)

YY = month of manufacture
WW = year of manufacture

Bradford White

ex. BH6511396 (YMxxxxxxx) = B=2005 & H=August

The Bradford White rating plate is the most difficult to decode.

The year of manufacture is noted by the first letter of the serial number, the month is the second letter. The decoding is based on the following format (also see chart below):
Year Decoder: G = 1990; H = 1991; J = 1992; K = 1993; L= 1994; M= 1995; N= 1996; P= 1997; S= 1998; T= 1999; W= 2000; X= 2001; Y= 2002; Z=2003; A= 2004; B=2005; C=2006; D=2007
Month Decoder: A= JAN; B=FEB; C=MAR; D= APR; E=MAY; F= JUNE; G=JULY; H= AUG; J= SEPT; K=OCT; L= NOV; M= DEC.

Note: Bradford White uses a 20-year letter designation rotation in serial numbers shown in the chart below. Therefore, please be aware that water heaters manufactured 20 years apart will have the same serial number “letter year” designation.

Click image to enlarge.

For a complete water heater dating chart visit

If your Tucson water heater is 10 years or older you should consider replacing it before it fails and potentially could cause damage.

If you are in need of water heater replacement call Just Water Heaters at 520-488-0816 or complete our online request form.