This guide can show you how to find the year of manufacture for Lennox Air Conditioners and Heaters/Air Handlers.
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Lennox AC Age
There are 4 different types of serial numbers to decipher the Lennox AC Age.
Type 1
This is the most common type. This type has 4 digits, a letter, and four other digits. The second two digits are the year and the letter is the month of manufacture.
Use the table below to find the month of manufacture.
| A is January | E is May | J is September |
| B is February | F is June | K is October |
| C is March | G is July | L is November |
| D is April | H is August | M is December |
For example, 1215M1234 would be December 2015.
Type 2
This type has 9 characters in the following order: Letter, 5 Numbers, 3 Letters. The first two digits are the year. The second to last letter is the month. Use the chart below to decode the month of manufacture.
| A is January | E is May | J is September |
| B is February | F is June | K is October |
| C is March | G is July | L is November |
| D is April | H is August | M is December |
Type 3
This type has 2 numbers, a letter, followed by 2 numbers, two letters, and three digits. The first two digits are the day, the letter is the month, and the following two numbers are the year **in reverse**. Use the chart below to find the letter’s respective month of manufacture.
| A is January | E is May | J is September |
| B is February | F is June | K is October |
| C is March | G is July | L is November |
| D is April | H is August | M is December |
For example, 12A56JK123 would be January 12, 1965.
Type 4
This type is all numbers. The last 4 are the year of manufacture and week of manufacture, respectively.
For example, 1234560212 would have a year of manufacture of 2002, week 12.
Lennox Heater/Air Handler Age
The air handlers and heaters for Lennox units follow the same types above for air conditioners.
Conclusion
More details can be found from Lennox
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