The short answer is once a year. The useful answer depends on what you burn and how much of it.
The annual baseline
Every wood-burning fireplace, insert or stove should be swept and inspected annually, before the heating season. Gas appliances need an annual service too — not for creosote, but to verify venting, combustion and blockages such as bird nests.
The burn-volume rule
- Under one cord per season: annual sweep is plenty
- One to three cords: annual sweep, mid-season visual check
- Over three cords, or you heat primarily with wood: sweep every six to nine months
- Any burning of unseasoned or softwood: shorten the interval by a third
Signs you should not wait
- Smoke rolling back into the room
- A tar or campfire smell when the fireplace is cold
- Black flakes falling into the firebox
- Slow lighting or a fire that will not stay going
- Any animal noise in the flue
Why insurers care
Ontario insurers increasingly request a current inspection report on wood-burning appliances at renewal, and a denied claim after a flue fire is a far more expensive problem than an annual sweep.
FAQ