If a chimney fire is happening now: get everyone out of the house and call 911 from outside. Shut the appliance's air controls only if that can be done safely as you pass. Never open the firebox door to see what is happening.
A chimney fire is burning deposit inside the flue, and it can be either dramatic or almost silent. The loud version announces itself with a roaring or rushing sound, dense smoke and sparks from the top, and an intensity of heat that is obviously wrong. The quiet version burns slowly, does its damage, and goes out without anybody realising what happened. Both can crack flue tiles, break the mortar joints between them and open a path for the next fire to reach the framing around the chimney. The single most important thing after a chimney fire is not the fire itself but what comes after it: the system must have a Level 2 inspection, with a camera scan of the whole flue, before anything is burned in it again. The pattern behind most serious chimney incidents is a first fire that was survived and never investigated.
Checks you can do safely
- After the event, look for puffy or honeycombed creosote in the firebox and base
- Check the cap and the top of the stack from the ground for discolouration or damage
- Look for pieces of flue tile or creosote in the clean-out
- Check for cracks in visible masonry and any smell of smoke in adjoining rooms
- Feel, do not open, walls and ceilings near the chimney for unexpected warmth
- Do not relight the appliance to test whether it happens again
Chimney fire: causes in the order worth checking
Emergency: leave the building and call 911 or your gas utility from outside
| Possible cause | Rank |
|---|---|
| Creosote built up in the flue, most often from burning wet wood | Most common |
| An appliance run too low for too long, letting smoke condense instead of leaving | 2 |
| A flue that is oversized or cold, so gases cool before they get out | 3 |
| A chimney that has gone more than a season without being swept | 4 |
| Burning rubbish, painted or treated wood, or cardboard | 5 |
| A blocked cap or screen restricting the flue | 6 |
Services this maps to
Related problems
- The Carbon Monoxide Alarm Went Off: What to Do
- Chimney Draft Problems: My Stove or Fireplace Will Not Draw
- Smoke Is Coming Into the Room Instead of Up the Chimney
- Buying a House With a Fireplace, Stove or Unused Chimney
If what you have is not chimney fire after all, the full list of chimney problems is grouped by urgency, and the service triage tool takes a symptom and returns the stop condition and the service it maps to.
Common questions about chimney fire
How do I know it was a chimney fire and not just a hot fire?+
A chimney fire commonly announces itself with a roaring or aircraft-like noise, dense smoke or sparks from the top and an unusual intensity. Afterwards, puffy honeycombed creosote, warped metal, a discoloured cap, cracked tiles or creosote fragments in the base are the physical evidence.
The fire went out by itself. Is that the end of it?+
No, and this is the most dangerous assumption in the subject. A fire that burned itself out can still have cracked the tiles and opened the joints. The chimney may now have a path to the framing that it did not have before, and nothing about that is visible from the room.
Can I use the stove again tonight?+
No. Not until a Level 2 inspection has established what the fire did. Skipping that inspection is the clearest stop-use situation in chimney work, and it is the one where people most often carry on because the house looks fine.
What does the inspection look for?+
Cracked or displaced flue tiles, failed joints between them, damage to a metal liner, heat damage to the structure and the framing around the chimney, and any change in clearances. The camera scan is the part that reaches where the damage commonly is.
Will my insurance cover it?+
A chimney fire is a sudden event, not gradual deterioration, which is broadly the more favourable side of that distinction, but insurers commonly ask whether the chimney had been maintained. Your inspection report and any sweeping records are what the conversation turns on.
How fast do I need the inspection?+
Before the next fire, whenever that would be. There is no urgency in the middle of the night if the fire is out and the fire service has cleared the house, and there is real urgency about not relighting it in the meantime.
What causes chimney fires in the first place?+
Creosote, and creosote comes from smoke cooling and condensing instead of leaving. Wet wood, a stove damped down too far, an oversized or cold flue and a long gap since the last sweep are the four usual contributors, often in combination.
Could it happen in a pellet stove?+
Far less likely, because pellet appliances produce fly ash, not heavy creosote. Not impossible, though: a badly neglected vent with an appliance burning poorly can accumulate enough. The bigger pellet risk is blockage instead of fire.
Does a chimney fire always damage the chimney?+
Not always, and that is why it gets inspected, not assumed either way. Some flues come through intact. The point is that you cannot tell which you have from inside the room, and the consequence of guessing wrong is a house fire.
What if the fire department already checked it?+
Fire crews check that the fire is out and the building is safe, which is a different question from whether the flue is intact enough to use again. They will ordinarily tell you to have it inspected before you use it, and that is the right advice.
How do I make sure it does not happen again?+
Burn dry wood, run the appliance hot enough that the flue stays warm, have the flue swept on an interval matched to how much you burn, and get the annual inspection so a developing problem is found before it becomes the fuel for a fire.
There is a smell of smoke in the room above. What does that mean?+
Potentially that combustion products are escaping the flue somewhere they should not, which after a chimney fire is exactly the finding that matters. Treat it as a reason to keep the appliance off and to mention it specifically when you book the inspection.