Serial number age decoders by brand
Each manufacturer hides the build date in the serial number in its own way, and most have changed the scheme at least once. Choose a brand to see every format it has used, or decode a serial here.
Find the age from the serial number
Need it on paper? for every brand on this page.
Water heaters
| Brand | Current date code | Example |
|---|---|---|
| A. O. Smith | Skip a leading letter if there is one. The first two digits are the year and the next two are the week of that year. | 1210A002243 |
| American | The first two digits are the year and the next two are the week of that year. | 9950123040 |
| Bradford White | The first letter is the year and the second letter is the month. A serial with eight digits after the two letters was built in December 2007 or later. | KE12345678 |
| GE | The letter just before the digits is the plant. The first two digits after it are the week and the next two are the year. | M141209135 |
| Kenmore | Skip a leading letter if there is one. The first two digits are the year and the next two are the week of that year. | 1210A002243 |
| Navien | Skip the four-digit model code and the letter after it. The next two digits are the year. The character after them is the month: 1 to 9 for January to September, then X, Y and Z for October, November and December. The two digits after the month are the day. | 7414C14X1771143 |
| Reliance | Skip a leading letter if there is one. The first two digits are the year and the next two are the week of that year. | 1210A002243 |
| Rheem | The letter just before the digits is the plant. The first two digits after it are the week and the next two are the year. | M141209135 |
| Richmond | The letter just before the digits is the plant. The first two digits after it are the week and the next two are the year. | M141209135 |
| Rinnai | The first letter is the year, starting with A for 2009. The second letter is the month, A for January through M for December with the letter I left out. | NK.CA-129326 |
| Ruud | The letter just before the digits is the plant. The first two digits after it are the week and the next two are the year. | M141209135 |
| State | Skip a leading letter if there is one. The first two digits are the year and the next two are the week of that year. | 1210A002243 |
| Whirlpool | The first two digits are the year and the next two are the week of that year. | 9950123040 |
Furnaces, AC and heat pumps
| Brand | Current date code | Example |
|---|---|---|
| Amana | The first two digits are the year and the next two are the month. | 0109145052 |
| American Standard | The first two digits are the year and the next two are the week. | 130313596L |
| Armstrong Air | The first two digits are the plant. The third and fourth digits are the year. The letter after them is the month, A for January through M for December with the letter I left out. | 1611A12345 |
| Bryant | The first two digits are the week of the year and the next two digits are the year. | 4006A17330 |
| Carrier | The first two digits are the week of the year and the next two digits are the year. | 4006A17330 |
| Coleman | The second and fourth characters are digits. Read together they are the year: 0 and 5 make 2005. The letter between them is the month. | W0K5896070 |
| Comfortmaker | The first letter is the plant. The two digits after it are the year and the next two are the week of that year. | E072514528 |
| Daikin | The first two digits are the year and the next two are the month. | 1602393269 |
| Ducane | The first two digits are the plant. The third and fourth digits are the year. The letter after them is the month, A for January through M for December with the letter I left out. | 1611A12345 |
| Goodman | The first two digits are the year and the next two are the month. | 1804165082 |
| Heil | The first letter is the plant. The two digits after it are the year and the next two are the week of that year. | E072514528 |
| Lennox | The first two digits are the plant. The third and fourth digits are the year. The letter after them is the month, A for January through M for December with the letter I left out. | 5899L17212 |
| Luxaire | The second and fourth characters are digits. Read together they are the year: 0 and 5 make 2005. The letter between them is the month. | W0K5896070 |
| Nordyne | Skip the first three characters. The fourth and fifth characters are the year and the sixth and seventh are the month. | FGA030310579 |
| Payne | The first two digits are the week of the year and the next two digits are the year. | 4006A17330 |
| Rheem | Find the last letter in the serial. The two digits after it are the week and the next two are the year. | W301745243 |
| Ruud | Find the last letter in the serial. The two digits after it are the week and the next two are the year. | 7351M280616735 |
| Tempstar | The first letter is the plant. The two digits after it are the year and the next two are the week of that year. | E072514528 |
| Trane | The first two digits are the year and the next two are the week. | 130313596L |
| York | The second and fourth characters are digits. Read together they are the year: 0 and 5 make 2005. The letter between them is the month. | W0K5896070 |
Appliances
| Brand | Current date code | Example |
|---|---|---|
| Amana | The first letter is the plant. The second character is the year, as a letter or a digit. The two digits after it are the week. | M44819595 |
| Bosch | Use the FD number on the rating plate, not the serial number. Add 20 to the first two digits and keep the last two digits of the sum: that is the year. 91 is 2011 and 03 is 2023. The next two digits are the month. | FD 9111 00449 |
| Frigidaire | The third character is the last digit of the year. The two digits after it are the week. The first two characters are the plant and the product. | VF52200000 |
| GE | The first letter is the month and the second letter is the year. Both use the same twelve letters, and the year letters repeat every 12 years. | LT081195Q |
| Kenmore | Follows the code of the company that built the unit. The first three digits of the model number show which one. | |
| KitchenAid | The first letter is the plant. The second character is the year, as a letter or a digit. The two digits after it are the week. | C60842986 |
| LG | The serial starts with three digits. The first is the last digit of the year and the next two are the month. | 603KWWZ73713 |
| Maytag | The first letter is the plant. The second character is the year, as a letter or a digit. The two digits after it are the week. | M44819595 |
| Samsung | Count to the eighth character: it is the year letter. The ninth character is the month, 1 to 9 for January to September, then A, B and C for October, November and December. | J0V07DDD801404K |
| Whirlpool | The first letter is the plant. The second character is the year, as a letter or a digit. The two digits after it are the week. | C60842986 |
Start from the equipment instead
- How old is my water heater?Tank and tankless, by serial number
- How old is my furnace?Gas, oil and electric furnaces
- How old is my AC unit or heat pump?Central air conditioners and heat pumps
- How old is my refrigerator?Refrigerators and freezers
- How old is my appliance?Washers, dryers, dishwashers, ranges