How to Find the Manufacture Date on a Lennox Air Conditioner

February 1, 2024 | Air Docs | Air Conditioning

With the summer heat slowly creeping up, it’s important to ensure your Lennox air conditioner is ready to cool you off. One crucial piece of information you should know is the manufacture date of their unit, as knowing it helps with a ton of HVAC-related things, like warranty claims, maintenance schedules, and troubleshooting purposes. Sure, they’re expected to last up to 15 years but you still want to be aware of the manufacture date.

You might be wondering how to find the manufacture date of the Lennox air conditioner. Well, the dates on Lennox air conditioners are presented in different formats on different models. Today’s article will take you through all the steps for figuring out where the manufacture date on your Lennox air conditioner, regardless of the format used.

Determining the Manufacture Date of a Lennox Air Conditioner

Before we dive into locating the manufacture date, you must understand the structure of the serial number of a particular Lennox model. It’s this number that helps determine the age of the device along with prudent manufacturing details. The model number, however, is important for identifying the unit’s features, but it doesn’t directly indicate the manufacture date.

Lennox serial numbers are usually a combination of letters and numbers. As for the format, it can vary depending on the year of production. You can find the serial number on the rating or data plate, which is on the unit’s exterior, next to the service panel. In most cases, there’s a tag containing the serial number, carrying a label such as “Serial #” or “S/N.”

If you can’t find the manufacture date on the data plate, the next place to check is inside the electrical control box. Some Lennox air conditioners contain a sticker with the manufacture date on the inside of the control box cover. Accessing the control box might require you to unscrew a panel or two, so make sure to turn the unit’s power off before opening it.

If you still can’t locate the manufacturer date, you need to consult the owner’s manual and reach out to Lennox customer support or an authorized service provider for specific instructions.

Understanding the Styles of Lennox Air Conditioner Serial Numbers

Lennox uses different styles of serial numbers on their air conditioner models, but since we can’t cover them all, we’ll take a look at the most commonly used ones:

Ten Characters: Numbers and One Letter. A system of serial numbers used by Lennox from 1974 to the present, it was the first method of marking Lennox Air Conditioners. It contains 10 characters, the third and fourth of which represent the year of manufacture. The fifth character, which is a letter, corresponds to the month of manufacture. Here’s a breakdown of the monthly codes:

A – January
B – February
C – March
D – April
E – May
F – June
G – July
H – August
J – September
K – October
L – November
M – December

For example, if the serial number is 5207K24862, the manufacture date would be October 2007.

Nine Characters (Mixed Letters & Numbers). The second style was used by Lennox, mostly between the late 1970s and early 1990s. Containing 9 characters, it begins with a letter, followed by 5 numbers, and ends with another 3 letters.
Ten Characters (Mixed Letters & Numbers). One of the earliest serial number styles, not seen often these days. It marked Lennox’s models in the 1960s and 1970s using. The combination of 10 characters, involving mixed numbers and letters, also contained the manufacture date.
Ten Characters (Numbers Only). Used until recently, the fourth style Lennox air conditioner serial numbers consist of 10 characters, all of which are numbers.

Common Challenges in Reading the Lennox Manufacture Date

While locating the manufacture date on your Lennox air conditioner is generally pretty easy, you might run into some challenges from time to time. A common one is a faded serial number due to elements such as sunlight or moisture.

In such a case, you can take a few steps to overcome this challenge. First, try using a flashlight or a bright light source to illuminate the area, which may make the characters more recognizable. Alternatively, you can gently clean the area around the serial number with a mild cleaning solution. Stay away from abrasive materials, as they can damage the unit’s surface.

If all else fails, contacting Lennox customer support is your final option. You’ll need to supply characters you might be able to read in order to receive the full one’s serial and model number.

Why Do You Need to Know the Manufacture Date?

There are several reasons to know where to find the manufacture date of your Lennox air conditioner. First, a manufacture date determines if your unit is still under warranty. Since most Lennox air conditioners expire after a specified period, the manufacture date helps you figure out if your unit is still eligible for warranty claims.

Additionally, the manufacture date helps you create a maintenance schedule for the air conditioning unit. Tasks like cleaning the filters, checking coolant levels, and inspecting the electrical components require a precise maintenance schedule.

There’s also the fact that the manufacture date defines the operating lifespan of your air conditioner. HVAC systems’ service design life is typically around 10-15 years, primarily for condensing units. Knowing the manufacturing number of your Lennox unit allows you to plan for potential replacements or upgrades.

Finally, there’s the aspect of troubleshooting, where knowing a unit’s manufacturing number can help service technicians diagnose potential problems quickly and efficiently.

Tips and Tricks for Locating the Lennox HVAC Manufacture Date

Locating and reading the manufacture date on your Lennox air conditioner can become extremely easy by following these useful tips and tricks:

Document the Serial number: Make sure to document the serial number before you attempt to locate the manufacture date. This way, you can easily communicate it to Lennox customer support if needed.
Use a Magnifying Glass. Some Lennox HVAC units have small and intricately printed serial numbers. This might make it difficult to read the characters, so an easy way to remedy visibility is by using a magnifying glass.
Take Photographs. If you’re concerned about the serial number (along with the manufacture date) fading over time, take clear photographs of the number and keep them accessible.
Keep a Maintenance Log. While this is mostly a task for Lennox maintenance services, if you want to be precise about your Lennox air conditioner maintenance, keeping a maintenance log yourself is a good idea. That way, you can keep track of any maintenance tasks like filter replacements or unscheduled repairs.

Wrapping Up

Remember that knowing how to find the manufacture date on your Lennox air conditioner is essential not just for warranty coverage but also for maintenance scheduling and troubleshooting. If cracking the code and locating the manufacture date on your Lennox air conditioner proves to be a nuisance, you should turn to a service that can decipher it for you. We at AirDocs Heating & Cooling are available any time of day, so feel free to contact us, and we’ll be happy to answer any air conditioning questions you may have, regardless of whether they’re about the manufacture date or other potential issues.