How old is my LG?
Type your LG serial number below to get the month and year it was built. 1 documented LG serial format, covering 2000 to today.
The serial number is on the metal rating plate. On a furnace it is usually inside the front door on the side wall; on an outdoor AC or heat pump it is on the back or side of the cabinet, near the refrigerant lines.
Type the LG serial exactly as printed. Spaces, dashes and lowercase are all fine.
LG serial number formats
Year digit plus month
2000 to present
The first digit is the year and the next two are the month, but LG reuses the year digit every ten years, so the serial alone cannot pin the decade. Check the rating plate: LG usually prints the manufacture date on it directly.
705ABCDEFG reads as May 2007 or May 2017
Source: HowToLookAtAHouse.com (licensed home inspector) · checked 2026-08-25
Where to find the serial on a LG
- Gas furnace: open the front door. The rating plate is on the inside side wall, usually near the top.
- Outdoor AC or heat pump: a metal or foil plate on the back or side of the cabinet, near where the copper lines enter.
- Mini-split: on the side of the outdoor unit, and on the indoor head behind the front flap or on its right side.
- Photograph the plate rather than copying it by hand. Misreading 0 for O, 1 for I or 5 for S is the most common reason a lookup fails.
Is your LG showing an error code?
Age tells you where the unit sits in its life. The fault code tells you what is wrong right now. We have 48 LG codes, each quoted from the manufacturer's own manual.
HVAC Code Lookup publishes these decoding rules from public industry references, not from LG. If the rating plate prints an explicit manufacture date, trust the plate over any decoder.