Typical signs
- Smoke or gas odour, abnormal soot, weak draft or a CO alarm.
- Spalled masonry, open joints, missing cap or water in the firebox.
Where it is often found
- Fireplaces, wood stoves, fuel-burning appliances, masonry chimneys and metal vents.
What it can mean
- Creosote build-up, blocked or inadequate flue, deteriorated masonry or negative indoor pressure.
What to check next
- Check maintenance history, CO alarm operation and signs of water entry.
Reasonable immediate actions
- Stop using the appliance if smoke spillage or a CO alarm occurs.
When to stop and call a professional
- Inspection and service by a qualified professional are required whenever draft, creosote or masonry is in doubt.
Prevention
- Regular service, suitable fuel, required clearances and adequate makeup air/ventilation.