How old is my Laars water heater?
Serial number age decoder for Laars tank water heaters: 2 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: C00B01803
- Laars water heater serial numbers in the era not stated format encode the year as digits 2-3 (YY; 00 = 2000) and the month as letter 1 (A=Jan..M=Dec, I skipped) (source: building-center.org).
- Example: serial C00B01803 decodes to March 2000.
- Laars water heater serial numbers in the before 1999 format encode the year as digits 1-2 (19YY) and the not encoded (source: building-center.org).
- Example: serial 8408375 decodes to 1984.
- Laars's official lookup at laars.com returns warranty / registration lookup.
Format eras
- before 1999 VERIFIED
#######digits 1-2 (19YY) - era not stated VERIFIED
A##A#####digits 2-3 (YY; 00 = 2000)
How to read the serial
before 1999 formatVERIFIED
Shape ####### · example 8408375 · confidence medium
- Year
- digits 1-2 (19YY)
- Week or month
- not encoded
Example: serial 8408375 decodes to 1984.
era not stated formatVERIFIED
Shape A##A##### · example C00B01803 · confidence high
- Year
- digits 2-3 (YY; 00 = 2000)
- Week or month
- month = letter 1 (A=Jan..M=Dec, I skipped)
- Plant
- letter 4 (unpublished)
| Month code | 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 |
| Plant code | Plant |
|---|---|
| A | Jan |
| B | Feb |
| C | Mar |
| D | Apr |
| E | May |
| F | Jun |
| G | Jul |
| H | Aug |
| J | Sep |
| K | Oct |
| L | Nov |
| M | Dec |
Example: serial C00B01803 decodes to March 2000.
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 Laars 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
- 9-char letter-month + YY + letter + 5 digits. Teledyne Laars era also used 7-digit YY##### serials. laars.com/support/warranty is registration only (no lookup).
Sources
- https://www.building-center.org/laars-hvac-age/
- https://www.building-center.org/teledyne-laars-water-heater-age/
- img: Laars-Date-of-Manufacture_Serial-Number-Nomenclature1.png
- img: TELEDYNE-Date-of-Manufacture-Serial-Number-Style-2.jpg
- https://www.laars.com/support/warrantyofficial