Why Your Southwest Philly Fireplace Backs Smoke Into the Room
A fireplace that pushes smoke into the living room instead of up the flue has a draft problem, and there are several common causes. Here is how to figure out why your fire will not draw.
How a chimney is supposed to draft
A fireplace that sends smoke up the flue rather than into your living room is doing so because the chimney is drafting, drawing the hot combustion gases up and out and pulling fresh air in to feed the fire behind them. Draft is driven by the fact that the warm gas in the flue is lighter than the cool air outside, so it rises, and as it goes up it pulls the smoke along with it and draws replacement air into the firebox. When everything is working, that draw is strong and steady, the smoke goes where it should, and you never think about any of it. When a fire backs smoke into the room, it means that draw has been disrupted somewhere, and the trick to fixing it is figuring out where.
Draft problems are among the most common chimney complaints we hear about in Southwest Philadelphia, and they are also among the most varied in cause, which is why a fireplace that smokes is worth diagnosing rather than guessing at. The same symptom, smoke in the room, can come from a blocked flue, a cold chimney, a flue that is the wrong size, a draft fighting the wind, or simply a damper or a fire that is not set up right. Sorting out which it is, is the whole job, because the fix for one cause does nothing for another.
The common causes of a smoking fireplace
The first thing to rule out is a blockage, because a flue that is partly closed off cannot move the smoke. An animal nest in the smoke shelf, debris fallen in through an uncapped flue, a heavy creosote buildup, or a damper that is rusted partly shut all narrow the path the smoke needs, and on a neglected chimney any of them can be the culprit. The second common cause is a cold flue. A chimney full of cold, dense air resists the warm smoke trying to rise through it, especially on the first fire of the season or on a chimney that runs up an exterior wall, and the fire smokes until the flue warms enough to establish the draw.
Beyond those, the causes get more particular. A flue that is too large for the fireplace lets the gases cool and slow before they can build a strong draw, while one too small cannot carry the volume. The chimney may be fighting the wind, which on the exposed Southwest Philly sites near the open corridor can down-draft and push smoke back into the room on gusty days. The house itself may be starving the fire of air if it is tightly sealed and the fire has no replacement air to draw. And sometimes the issue is simpler, a closed or partly closed damper, a fire built too far forward in the firebox, or wet wood that smolders instead of burning hot. Each of these has a different fix.
- A blockage: animal nest, debris, heavy creosote, or a seized damper
- A cold flue resisting the warm smoke, common on the first fire
- A flue that is the wrong size for the fireplace
- Wind down-drafting on exposed sites near the open corridor
- A tightly sealed house starving the fire of replacement air
- A closed damper, a poorly built fire, or wet wood
What you can check, and what needs a professional
Some of the causes a homeowner can check and address without any help. Make sure the damper is fully open before you light a fire, which sounds obvious but is a common oversight. Burn only dry, seasoned wood, because wet wood smolders, smokes, and builds creosote rather than burning hot enough to drive a good draft. Build the fire toward the back of the firebox rather than forward at the opening. And on the first fire of a cold day, prime the flue by warming it, holding a lit roll of newspaper up near the open damper for a minute to start the warm air rising before you light the fire itself. These simple steps solve a fair number of mild draft complaints on their own.
Other causes need a professional, because they are inside the flue or built into the chimney. A blockage needs to be found and cleared, which a sweep handles, and a heavy creosote buildup needs sweeping regardless. A flue that is the wrong size, a chimney that consistently down-drafts in the wind, or a draft that is marginal for structural reasons may need a cap suited to stabilizing the draft, an adjustment to the flue, or other measures that an inspection can identify. The point is that a fireplace which smokes every time, rather than just on the first cold fire, has a cause that is worth diagnosing, because the right fix depends entirely on which of the many possible causes is actually at work.
Diagnosing it rather than guessing
Because a smoking fireplace can come from so many different causes, the worst approach is to guess and throw money at the wrong one. The right approach is an inspection that runs a camera up the flue to rule out a blockage, checks the flue size and the damper, looks at the chimney's height and termination in relation to the wind and the nearby rooftops, and considers whether the house is starving the fire of air. With the actual cause identified, the fix is straightforward, and it is the fix that solves your particular problem rather than a generic remedy that may do nothing.
On Southwest Philadelphia's older rowhome chimneys, draft problems often come down to a blockage, a wrong-sized or deteriorating flue, or wind on an exposed site, all of which an inspection sorts out. If your fireplace backs smoke into the room every time you use it, that is not something to live with or to guess at, it is a sign the chimney needs a proper look. Once we know why it smokes, we can tell you honestly what it takes to make it draw the way it should, and put that in writing before any work begins.
A Southwest Philadelphia fireplace that backs smoke into the room has a draft problem with a findable cause, whether a blockage, a wrong-sized flue, or wind on an exposed site. We will scan the flue, diagnose it, and tell you honestly what it takes to fix it. Call 215-618-4690.
Ready to get it looked at? call 215-618-4690 any time.