First thing worth correcting: these levels are NFPA’s, not a chimney company’s. They are defined in NFPA 211 Chapter 15, the national standard for chimneys, fireplaces, vents and solid fuel-burning appliances.
Saying “CSIA Level 2” is industry shorthand. Saying “NFPA 211 Level II” is both correct and more authoritative, and it means you can ask a contractor which clauses of the standard they are actually performing.
The standard also sets the governing principle up front: the scope, the areas examined and the degree of invasiveness shall be appropriate for the conditions giving rise to the inspection. The level follows your situation, not a price list.
Level I: the annual baseline
When it applies: verifying the chimney is suitable for continued service, under the same conditions and with the same appliance.
Required, per §15.3.1, in three cases:
- During the annual inspection required by §14.2
- During routine cleaning of a flue
- When an appliance is replaced with one of similar type, input rating and efficiency
What it covers: readily accessible portions of the chimney structure and flue, verification that flues are free of combustible deposits and obstruction, and examination of appliances, connectors and surroundings for proper clearances, damage and observable malfunction.
Note the word readily. Level I examines what can be reached without removing panels, doors or coverings.
Level II: sale, fire, relining, or a changed appliance
This is the one that gets skipped, and §15.4.1 requires it in four situations:
- Upon sale or transfer of the property
- After a building or chimney fire, weather or seismic event, or other incident likely to have caused damage
- Prior to relining a flue or replacing a flue lining
- When an appliance is added or removed, or replaced with one of dissimilar type, input rating or efficiency
What it adds over Level I:
- All accessible areas, including accessible attics, crawl spaces and basements, reached without removing permanently attached parts of the building
- Examination of the flue interior with video scanning equipment
- Verification of proper clearances from the chimney to combustibles at accessible locations
- Evaluation of the correct lining material and flue sizing for the connected appliance
If you are buying a house with a fireplace, this is the inspection to ask for. If a contractor proposes relining without having scanned the flue, they are quoting a guess.
Level III: only what the others cannot reach
Level III is deliberately narrow. §15.5.1 restricts it to only those areas suspected of malfunction or damage that a Level I or II cannot properly evaluate.
Required when:
- Investigating a fire or event known to have caused damage
- A hazard detected or suspected at Level I or II cannot be fully evaluated without access to concealed areas
It permits removal of building or chimney components, but only as necessary to reach the areas under inspection. Nobody should be selling a Level III as routine service.
And the annual requirement itself
NFPA 211 §14.2 is one sentence: chimneys, fireplaces and vents shall be inspected at least once a year in accordance with Section 15.2. §14.2.1 adds that cleaning, maintenance and repairs shall be done if necessary.
Note what it does not say: there is no fixed annual cleaning interval in the standard. The inspection is annual. The cleaning happens when the inspection calls for it.
In Oklahoma specifically
No Oklahoma statute requires a chimney inspection at sale. But NFPA 211 calls for Level II on transfer, and lenders and buyers’ agents commonly require one, so confirm what your transaction actually needs before setting a closing date.
Also worth knowing: performing the inspection is unlicensed work in Oklahoma, but anything the inspection recommends that touches the appliance or its venting is licensed work. Those may be two different people.