When do I open and close the damper on my wood-burning fireplace?
Open the damper fully before you light, and keep it wide open the whole time the fire burns — and until the coals are completely cold. Only close it once there's no heat, no glow, and no smoke at all, which usually means the next day. A closed damper over a live fire sends smoke and carbon monoxide into your home.
Open before the match, closed only when cold
The damper is the metal flap in the throat of the fireplace that opens and closes the chimney. Rule one: open it all the way before you light anything, so smoke has a clear path up and out. Reach up and confirm it's actually open — a lot of the 'my fireplace smoked the whole room' calls we get trace straight back to a damper someone forgot was shut.
Don't be tempted to choke the damper down partway to slow a fire or 'hold the heat.' All that does is push smoke into the room and coat your flue with creosote. Control a wood fire with how much wood you load, never by starving the chimney.
The closing rule keeps you safe
A wood fire's coals keep giving off carbon monoxide for hours after the visible flames are gone — and you can't see or smell it. Close the damper while there's still heat in that coal bed and you trap the CO in the house. So the rule is simple: the damper stays open until the ashes are stone cold, which for an evening fire usually means the following morning.
If you're ever unsure, leave it open. Losing a little warm air up the chimney overnight is a fair trade against carbon monoxide in your bedrooms.
Between fires and the off-season
When the fireplace is cold and you're not using it, close the damper. An open damper on an idle fireplace is an open hole in your house — it lets heated air escape and pulls cold mountain drafts down the flue all winter.
Older Asheville homes often have a throat damper that's warped or rusted and never quite seals — we see it weekly. A top-sealing damper or a chimney balloon stops that leak if yours won't close tight. Just remember to reopen it fully before the next fire. We inspect dampers and flues and can tell you what shape yours is in — call (828) 545-0525.
Related questions
- How soon after the fire dies down can I close the damper?
- What's the best way to build and light a fire in my wood-burning fireplace?
- Should I burn my fireplace with the glass doors open or closed?
- Does the damper have to stay open when I run vented gas logs?
- How do I use the damper in my wood stove's flue pipe, and when should I close it?
- How do I light the pilot light on my gas fireplace?
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