Smoke pushing into the room
The most obvious sign. If smoke spills out when the door is opened — or seeps from the seals during normal burning — the flue is restricted enough to disrupt the draught.
The fire won't draw, even with fresh kindling
A clean, well-built fire that struggles to catch and dies as soon as you close the door usually has a flue problem. If the symptoms are worse after a long off-season, suspect a blockage at the top.
A musty or smoky smell when the heater is cold
Especially on damp days. A partial blockage allows moist air to sit in the flue and push the smell back into the room.
Debris in the firebox
Twigs, leaves, or feathers in the firebox after a long pause are a clear sign that something has set up shop in the flue. Currawongs and starlings build surprisingly large nests.
Dark staining around the flue exit
Tar streaks, water marks, or soot patches on the ceiling around the flue penetration indicate condensate making its way back down — a sign the flue is not venting properly.
What to do
Don't climb the roof. Don't poke a stick down the cowl. Leave the heater unlit, ventilate the room if you've had smoke spillage, and book a check. We'll inspect from top and bottom and clear the blockage safely.
A note on safety: chimney and flue issues can become serious quickly. When in doubt, leave the heater unlit and call a qualified sweep — a short visit beats guessing.