Furnaces & AC / Coleman

How old is my Coleman HVAC unit?

ColemanChange

Ad space (kept empty until an ad network is approved)

Where to find the serial number

Look for “Serial” or “S/N” near the service connections

Coleman serial formats we can read

Dark = year, orange = month or week.

Split year around month letter

W0K5896070

September 2005.

Coverage and sources

Supports the split-year layout introduced in October 2004. Join digits 2 and 4 for the year; the month is letter 3. This alphabet skips I and J, so K means September. Earlier layouts are excluded.

References checked 2026-10-26.

www.building-center.org/coleman-hvac-age/
www.building-center.org/york-hvac-age/
www.building-center.org/wp-content/uploads/2016/04/YORK-Serial-Number-Style-1.jpg

Independent reference tool, unaffiliated with Coleman. Sources & method