How often should you inspect a chimney?
Updated July 2026
Have your chimney inspected every year: both CSIA and NFPA 211 call for at least an annual Level 1 inspection of any chimney in use. That is a separate job from sweeping. A sweep removes soot and creosote, while the inspection checks the liner, crown, cap, flashing, and masonry for the problems you cannot see from the hearth. The stakes are why it is annual: a cracked liner or a creosote-glazed flue is a chimney-fire and carbon-monoxide risk, and by the time it shows, the fix is often a rebuild.
What changes the interval
| Your situation | Interval | Why |
|---|---|---|
| Wood fireplace or stove, regular use | Level 1 yearly | Creosote and liner cracks are the core fire risk |
| Gas fireplace or gas furnace flue | Level 1 yearly | Blockages and liner gaps cause carbon-monoxide backup |
| Buying or selling the home | Level 2 inspection | Adds a camera scan of the full flue interior |
| After a chimney fire, quake, or storm | Level 2 before next use | Hidden liner and structural damage must be ruled out |
| Rarely used or capped-off fireplace | Level 1 yearly still | Animals, moisture, and debris get in either way |
| 1/8 inch of creosote in the flue | Sweep now | That is the threshold where a fire becomes likely |
The cost of skipping it
What skipping it costs: an unseen problem in a chimney is the dangerous kind. Creosote buildup fuels chimney fires that can spread into the framing, and a cracked liner or blocked flue can push carbon monoxide back into the house. The repair ladder is steep: a Level 1 inspection is $100 to $250 and a sweep $150 to $400, but a relined flue runs $2,500–7,000 and a full masonry rebuild climbs into the $5,000–15,000+ range. The inspection is what keeps you on the cheap end of that ladder.
How to do it (Book a certified sweep · $100–250 for a Level 1)
- Hire a CSIA-certified chimney sweep rather than a general handyman; the certification is the thing to check.
- Book it in late summer or early fall, before the heating season and the rush.
- Ask for the inspection and the sweep together so buildup gets removed and documented in one visit.
- Have them check the liner, crown, cap, flashing, damper, and masonry, and photograph anything questionable.
- Keep the written report; it matters for insurance and for selling the home later.
Knowing the interval is the easy half. OnOtto reminds you at the right interval, and it won't let you snooze it into next year. Tasks persist until they're done, and completing chimney inspections schedules the next one automatically.
Put this on autopilot, free for 30 daysFrequently asked questions
What is the difference between a chimney inspection and a sweep?
A sweep is the cleaning: a technician brushes soot and creosote out of the flue so it cannot catch fire. An inspection is the assessment: they examine the liner, crown, cap, flashing, damper, and masonry for cracks, blockages, and deterioration. You need both, and they are often done in the same visit, but they are not the same service. A flue can be freshly swept and still have a cracked liner that makes it unsafe, which only the inspection would catch.
What are the levels of chimney inspection?
NFPA 211 defines three. Level 1 is the annual baseline for a chimney in regular use with no known problems: a visual check of the accessible interior and exterior. Level 2 adds a video-camera scan of the full flue and is required when you buy or sell, change the fuel or liner, or after an event like a chimney fire or earthquake. Level 3 is invasive, opening walls or the crown to reach a suspected hidden hazard. Most homeowners only ever need Level 1 and the occasional Level 2.
Do gas fireplaces and furnaces need a chimney inspection too?
Yes. Gas burns cleaner than wood, so there is little creosote, but the flue can still crack, corrode, or get blocked by a bird nest or debris, and any of those can push carbon monoxide back into the house instead of up and out. An annual Level 1 inspection checks the liner and clears the flue. This is also why every home with a fuel-burning appliance should keep working carbon-monoxide detectors on each level.
What happens if I never inspect my chimney?
Two things build quietly. Creosote accumulates in a wood flue until a hot fire ignites it, and a chimney fire can crack the liner or spread into the framing. Meanwhile, water and freeze-thaw damage the crown and masonry from outside, and a deteriorating liner can leak combustion gases. The costs escalate from a missed $150 sweep to a five-figure rebuild or, worse, a fire or CO event. See the cost of never cleaning your chimney.