How to Decode Lennox Serial Numbers

Step-by-step guide to decoding any Lennox HVAC serial number. Learn the Year-Week (YYWW) format, what each digit means, and get instant results with our free decoder tool.

Step 1: Locate the Lennox Label

Find the data plate on your Lennox unit. It's usually on the side panel (outdoor units) or inside the cabinet door (indoor units). The label contains both the model number and serial number.

Step 2: Identify the Serial Number Format

Lennox uses a Year-Week (YYWW) serial number format. Do not confuse the serial number with the model number -- the serial is unique to each unit, while the model identifies the product line.

Step 3: Enter in the Decoder

Type your Lennox model or serial number into HVAC Decoder Pro. Our decoder instantly parses Lennox's encoding format and extracts manufacturing date, capacity, refrigerant type, and SEER rating.

Step 4: Review Your Results

The decoder displays a complete profile: manufacturing date, tonnage, BTU capacity, refrigerant type with phase-out status, SEER rating, and a color-coded condition indicator (Green = Good, Yellow = Aging, Red = Replace Soon).

Lennox Serial Number Format Reference

Format

Year-Week (YYWW)

Example Serial

2314B67890

Lennox serial numbers encode the manufacturing date, production facility, and unit sequence number. Our decoder handles all known Lennox serial number formats automatically.

What Your Lennox Serial Number Reveals

Pos.FieldValueMeaning
1-2Year of manufacture232023
3-4Week of manufacture14Week 14 (April)
5Plant identifierBManufacturing facility B
6-10Sequential number67890Production sequence #67890

FAQ

Where is the serial number on a Lennox unit?

On the metal data plate -- side/back panel for outdoor units, inside the cabinet door for indoor units.

How do I read a Lennox serial number?

Lennox uses Year-Week (YYWW) format. Example: "2314B67890". Our decoder parses it automatically.

How old is my Lennox HVAC unit?

Enter your serial number in our decoder -- the manufacturing date is encoded in the Year-Week (YYWW) format.