Level 1 — annual maintenance
For a system in continuous use with no changes and no known problems. The technician checks readily accessible exterior and interior portions, confirms the flue is clear of obstruction and combustible deposits, and verifies basic structure and connections.
Level 2 — sales, changes and incidents
Includes everything in Level 1 plus a video camera scan of the entire flue interior and access to attics, crawlspaces and the roof. It is the correct inspection when buying or selling a home, after a chimney fire, lightning strike or storm, or when switching fuel types or installing a new appliance.
Level 3 — when hidden damage is suspected
A Level 3 involves removing components or portions of the structure — a chase cover, a wall section — to reach concealed areas. It is only recommended when a Level 2 shows evidence of a serious hazard that cannot be evaluated any other way.