Smoke curling out under the lintel
"Smoke rolls out the top of the opening when the fire starts." "The living room smells like a campfire the next morning." "It only smokes when the wind comes off the water." Those complaints sound alike but usually point at different causes. A smoky fireplace is losing a tug of war between air pulling up the flue and air pushing back down it.
Draft is warm gas rising. Hot smoke climbs the flue and drags room air in behind it across the fire. Anything that cools that column, blocks it, shortens it, or sucks against it from inside the house sends smoke into the room instead. Here is each cause and the test that separates it from the others.
The flue is still full of cold air
What you notice: smoke spills for the first few minutes, then the fire settles and burns clean. It is worse on the first fire of the season and on foggy mornings.
What is going on: a masonry chimney on an outside wall fills with cool, heavy air between fires. Until the fire warms it, that cold plug sits over the firebox like a lid. In Long Beach the marine layer keeps chimneys cool much of the year, so a slow start is common even when nothing is wrong.
How it is told apart: hold a lit roll of newspaper up near the open damper for a minute before you light the kindling. If its smoke wavers and then turns upward, the flue was simply cold. A cold flue needs no repair, just a warm-up and small kindling first.
A damper plate hanging halfway
What you notice: smoke from the very first match that does not ease as the fire grows.
What is going on: a throat damper can rust, warp, or slip off its pivot so the plate hangs partway across the opening. The handle can read open while the plate has not moved.
How it is told apart: look up with a flashlight and work the handle through its full travel. A camera shows whether the plate swings all the way clear. A stuck or broken damper means repairing the frame and plate, or fitting a top-sealing damper at the crown instead.
The house is pulling harder than the chimney
What you notice: smoke only when the kitchen hood is running, the dryer is on, or every window is shut. Cracking a window near the fireplace clears it within a minute.
What is going on: negative pressure. Range hoods, bath fans, clothes dryers, and some furnaces all push air out of the house. That air has to come back in somewhere, and an open chimney is the easiest hole. New windows make it worse in older Craftsman and Spanish Revival homes that used to leak air freely.
How it is told apart: the window trick is the quick version. The careful version uses a manometer, a draft gauge that reads pressure in the flue with the fans on and then off. If the reading reverses when the hood starts, the house is the problem, not the chimney. The fix is makeup air, a vent that lets outside air in near the hearth, or changing which fans run while you burn. A CO meter comes along too, because a depressurized house can pull gas appliance exhaust backward.
A flue sized wrong for the opening
What you notice: it has always smoked, in any weather. Small fires behave. Big fires spill.
What is going on: proportion. The flue needs a cross section of very roughly one tenth of the fireplace opening, a bit more or less depending on its shape and the height of the chimney. A big firebox on a narrow flue overwhelms it. An oversized flue lets smoke spread, cool, and stall. A short chimney, common after a second-story addition raised the roof around it, does not make enough pull.
How it is told apart: measure the firebox opening and the flue, then compare. If the numbers are far apart, the options run from a smoke guard (a metal strip across the top of the opening that makes it smaller), to relining the flue at a matching size, to adding chimney height or a draft-inducing cap.
Something is sitting in the flue
What you notice: smoking that began recently in a fireplace that used to burn well, with grit on the hearth or a sharp creosote smell.
What is going on: creosote narrows the flue layer by layer. Nests, broken clay liner, or mortar from a crumbling smoke chamber can choke it outright. Many chimneys here were patched after the 1933 earthquake, and those older liners sometimes shed pieces.
How it is told apart: a camera scan. A choked flue usually clears with a sweep. Fallen liner or a broken smoke chamber is a repair job.
Afternoon wind curling over the roofline
What you notice: "it only smokes when the wind comes off the water." Calm nights are fine. The afternoon breeze brings smoke back down.
What is going on: wind striking a taller roof next door, a tree, or the ridge of your own house can roll down over the chimney top and press smoke back into the flue. Onshore breezes make this a regular pattern in Belmont Heights and near the shore.
How it is told apart: note the wind direction and time on the nights it smokes. If the pattern holds, the answer is usually a cap shaped to resist downdraft, or more chimney height.
The order we test in, and what it means for your bill
We test from cheapest to most involved: damper position, a newspaper or smoke pencil at the throat, the window test, the manometer with fans on and off, then a camera scan if the earlier steps have not explained it. That order keeps you from paying for a new liner when the answer was a range hood.
Your next step depends on which test fails. A cold flue costs you nothing. A choked flue is a sweep, from $210. A sizing problem, a broken damper, or a smoke chamber repair falls under fireplace repair, quoted in writing after the diagnosis with the reason for each line.
Send us a short video of the fire starting, with the damper handle in frame and a note on which fans were running, and we will reply with the test we would run first.
Before you strike the next match
- - Look up and confirm the damper plate is open. Do not trust the handle.
- Warm the flue with a rolled newspaper for a minute.
- Switch off the kitchen hood and bath fans, and crack a window near the fireplace.
- Check whether it is a no-burn day under Check Before You Burn before lighting at all.
- If the room smells of smoke hours later or anyone gets a headache, stop burning until it has been checked.
We look at smoky fireplaces all over Long Beach and down through the South Bay. If smoke is in the room tonight, let the fire die, open a window, and tap the call link at the top of the page. Tell us when the smoke starts and what was running, and we will say what to check before anyone drives over.
Did the tips leave the smoke where it was?
Then the cause is probably one a test at the hearth will show. Ramsey listens to how the fire behaves, runs the house as you do and names the reason. We work from San Pedro across the peninsula, Lomita, Torrance and Long Beach.
