How old is my Kenmore HVAC furnace?

Serial number age decoder for Kenmore HVAC furnaces: 1 format era, the decode rule in plain English, transcribed tables, and the official lookup.

Serial number decoder for Kenmore HVAC furnace

Serial no.

Type the serial from the data plate, not the model number. Nothing is sent anywhere; the tables are in this page.

Format example: 320100007S

Kenmore HVAC furnace serial numbers in the era not stated format encode the year as digits 3-4 = YY (320100007S = 2001) and the week as digits 1-2 (32) (source: building-center.org).
Example: serial 320100007S decodes to week 32 of 2001.
Kenmore HVAC's official lookup at kenmore.com returns warranty / registration lookup.

Format eras

era not stated VERIFIED
#########Adigits 3-4 = YY (320100007S = 2001)

How to read the serial

era not stated formatVERIFIED

Shape #########A · example 320100007S · confidence medium

Year: digits 3-4 = YY (320100007S = 2001)
Week or month: week = digits 1-2 (32)

Example: serial 320100007S decodes to week 32 of 2001.

Trap: Kenmore units built by ECR International (not ICP). Trailing S not always present. Same WWYY shape as Carrier/ICP style 1 minus the letter.

Where the data plate is on a furnace

Inside the furnace: remove the upper (burner) access door and look on the inside of the door, on the blower compartment wall, or on a sticker facing you at the burner deck.

General guidance, not brand-specific: the owner's manual or the installer can point to the exact spot. See the data plate guide.

For scale only: the InterNACHI Standard Estimated Life Expectancy Chart for Homes lists Furnace at 15 to 25 years of expected service (nachi.org). That chart is a guideline, not a prediction for your unit.

Official lookup: the authority

Open the official Kenmore HVAC lookup takes serial number; returns warranty / registration lookup; URL verified live

This site is a reference built from published tables. The manufacturer's own lookup wins whenever the two disagree.

What we could not confirm

Routing brand: the 3-digit MODEL prefix picks the factory (table in the Kenmore rule, 100+ prefixes transcribed from building-center's 2024 chart), then apply that maker's serial rule. Sears PartsDirect publishes per-prefix decode articles (110/106/253/363/402/417/596/795/796). kenmore.com/support curl 200 (support hub, no lookup).