How old is my Westinghouse Water Heaters water heater?
Serial number age decoder for Westinghouse Water Heaters tank water heaters: 4 format eras, the decode rule in plain English, transcribed tables, and the official lookup.
Type the serial from the data plate, not the model number. Nothing is sent anywhere; the tables are in this page.
Format example: 010419H20000667
- Westinghouse Water Heaters water heater serial numbers in the 2011 to 2021 format encode the year as digits 5-6 (20YY) and the month as digits 1-2; digits 3-4 = day of month per HTP official guide (building-center says week) (source: building-center.org).
- Example: serial 010419H20000667 decodes to January 2019.
- Westinghouse Water Heaters water heater serial numbers in the 1994 to 2011 format encode the year as letter 2 (4th char) (table below) and the month as letter 1 (A=Jan..L=Dec, I=Sep, 12 consecutive letters); day of month as digits 2-3 (source: htproducts.com).
- Example: serial I21M28666 decodes to September 2006.
- Westinghouse Water Heaters water heater serial numbers in the 2011 to 2021 format encode the year as digits 5-6 (20YY) after dropping a 2-digit prefix when the serial is 16 digits and the month as digits 1-2, day as digits 3-4; the letter = production line (source: htproducts.com).
- Example: serial 112116E2054485 decodes to November 2016.
Format eras
- 2021 to present VERIFIED
#######A#############digits 10-11 (20YY) - 2011 to 2021 PARTIAL
######A########digits 5-6 (20YY) - 2011 to 2021 VERIFIED
######A#######digits 5-6 (20YY) after dropping a 2-digit prefix when the serial is 16 digits - 1994 to 2011 VERIFIED
A##A#####letter 2 (4th char): A=1994 B=1995 C=1996 D=1997 E=1998 F=1999 G=2000 H=2001 I=2002 J=2003
How to read the serial
2021 to present formatVERIFIED
Shape #######A############# · example 3251200U4220450000188 · confidence high
- Year
- digits 10-11 (20YY)
- Week or month
- day of year = digits 12-14 (045 = Feb 14)
- Plant
- chars 8-9 = Ariston factory code (e.g. U4, 02, 35)
Example: serial 3251200U4220450000188 decodes to day 45 of 2022.
Listed under HTP in the source; Westinghouse Water Heaters is named in that format's family and the corporate link is an estimate, not a checked fact.
2011 to 2021 formatPARTIAL
Shape ######A######## · example 010419H20000667 · confidence medium
- Year
- digits 5-6 (20YY)
- Week or month
- month = digits 1-2; digits 3-4 = day of month per HTP official guide (building-center says week)
Example: serial 010419H20000667 decodes to January 2019.
Listed under Westinghouse water heaters in the source; Westinghouse Water Heaters is named in that format's family and the corporate link is an estimate, not a checked fact.
2011 to 2021 formatVERIFIED
Shape ######A####### · example 112116E2054485 · confidence high
- Year
- digits 5-6 (20YY) after dropping a 2-digit prefix when the serial is 16 digits
- Week or month
- month = digits 1-2, day = digits 3-4; the letter = production line
Example: serial 112116E2054485 decodes to November 2016.
Listed under HTP in the source; Westinghouse Water Heaters is named in that format's family and the corporate link is an estimate, not a checked fact.
1994 to 2011 formatVERIFIED
Shape A##A##### · example I21M28666 · confidence high
- Year
- letter 2 (4th char): A=1994 B=1995 C=1996 D=1997 E=1998 F=1999 G=2000 H=2001 I=2002 J=2003 K=2004 L=2005 M=2006 N=2007 O=2008 P=2009 Q=2010 R=2011
- Week or month
- month = letter 1 (A=Jan..L=Dec, I=Sep, 12 consecutive letters); day of month = digits 2-3
| Year code | Year(s) |
|---|---|
| A | 1994 |
| B | 1995 |
| C | 1996 |
| D | 1997 |
| E | 1998 |
| F | 1999 |
| G | 2000 |
| H | 2001 |
| I | 2002 |
| J | 2003 |
| K | 2004 |
| L | 2005 |
| M | 2006 |
| N | 2007 |
| O | 2008 |
| P | 2009 |
| Q | 2010 |
| R | 2011 |
| Month code | Month |
|---|---|
| A | January |
| B | February |
| C | March |
| D | April |
| E | May |
| F | June |
| G | July |
| H | August |
| I | September |
| J | October |
| K | November |
| L | December |
Example: serial I21M28666 decodes to September 2006.
Listed under HTP in the source; Westinghouse Water Heaters is named in that format's family and the corporate link is an estimate, not a checked fact.
Where the data plate is on a water heater
The rating plate is a large label on the side of the tank near the top or beside the control. The serial is printed on it, often beside the model number and the ANSI standard line.
General guidance, not brand-specific: the owner's manual or the installer can point to the exact spot. See the data plate guide.
For scale only: the InterNACHI Standard Estimated Life Expectancy Chart for Homes lists Water Heater (conventional) at 6 to 12 years of expected service (nachi.org). That chart is a guideline, not a prediction for your unit.
Open the official HTP lookup takes serial number; returns warranty / registration lookup; URL verified live
This site is a reference built from published tables. The manufacturer's own lookup wins whenever the two disagree.
What we could not confirm
- The 2011 to 2021 format is only partially confirmed (PARTIAL).
- Westinghouse Water Heaters is treated as sharing Westinghouse water heaters's format because the source lists it in that family; the corporate relationship itself is an estimate.
- Westinghouse Water Heaters is treated as sharing HTP's format because the source lists it in that family; the corporate relationship itself is an estimate.
- No official online lookup URL was verified for Westinghouse Water Heaters.
- Serial 010419H20000667 = HTP 2011-2021 style; building-center labels digits 3-4 'week' but the HTP official guide and the plate's own 1/4/2019 date show it is DAY of month. westinghousewaterheating.com now redirects to westinghouse.com tankless collection.
Sources
- https://www.building-center.org/westinghouse-water-heater-age/
- https://www.htproducts.com/literature/UnderstandSerialNumbers-2-2024.pdfofficial
- https://www.htproducts.com/literature/UnderstandSerialNumbers-2-2024.pdf (official Ariston/HTP decode guide)official
- https://www.building-center.org/htp-water-heater-boiler-age/
- https://www.building-center.org/ariston-water-heater-age/