LENNOX SERIAL NUMBER LOOKUP
Lennox serial number lookup
Find the manufacture date and estimated age of your Lennox air conditioner, heat pump, or furnace.
About this lookup
In the widely used Lennox format, digits three and four identify the year and the fifth character identifies the month; the letter I is skipped.
What it supports
Ten-character serials matching Lennox's documented ####A##### style.
If your serial does not match
Other documented Lennox serial shapes require a different rule and are not auto-decoded here.
Where to find the serial number
Check the side or rear of the outdoor unit, inside the furnace door, or on the air-handler cabinet. Copy the complete serial number, not the model number.