Why a Fireplace Insert Smokes Into the Room

When the Smoke Appears Tells You Why

A well installed insert burning dry wood should send almost all of its smoke up the chimney. The EPA puts it simply: properly installed, correctly used wood-burning appliances make very little smoke, and if you regularly see or smell it you may have a problem. Before you change anything, notice when the smoke shows up. Each timing points to a different cause.

If smoke is filling a room, put the fire out by closing the air control, open windows and get everyone into fresh air. Smoke carries carbon monoxide; a working CO alarm near bedrooms and in the same room as the insert, as the Regency manual recommends, is not optional.

• Only when the door opens: draft too weak at that moment, or the door opened too fast.
• Through the seams while burning: poor draft, a misplaced baffle or a bad connection.
• Only on lighting, then it clears: a cold flue or a house short of air.
• Behind or around the faceplate: smoke escaping the liner path into the old firebox.
• With one batch of wood only: the wood is wet.

Smoke Only When the Door Opens

Smoke at the open door is often a habit, not a fault. The Regency i2450-2 manual says to open the draft control fully for 10 to 15 seconds before slowly opening the door to refuel, and after burning on a low setting to open the door a crack and let the fire adjust before opening it all the way. Opening a smoldering insert wide in one move lets the smoke roll out before the chimney catches up.

If it still puffs with the air open and the door eased, the draft itself is weak, and the causes below apply.

Smoke Through the Seams While It Burns

The Regency manual warns that inadequate draft lets smoke leak out through the appliance and connector joints and puffs it back into the room. Two causes sit inside the insert. The baffles must be in place before every fire; the manual says smoke spillage and draft problems follow when they are out of position, and that forcing in too much wood can knock them loose. A door gasket that has compressed lets smoke and air through as well; the manual's latch adjustment tightens it.

The others sit above. The same manual requires a continuous liner from the insert to the top of the chimney. A short stub or no pipe at all leaves the smoke to find its way through a cold, oversized masonry flue, and an open damper throat lets smoke spill into the space behind the faceplate. Our guides on liners for inserts and the block-off plate explain both.

Smoke on Lighting, Then It Clears

A little smoke when the fire is first lit, until the chimney warms, is normal, according to the smoke troubleshooting notes in the Superior wood fireplace manuals; it should not continue. The fix is to warm the flue first. The Superior WRT manual suggests opening a nearby window, lighting a rolled-up piece of paper and holding it high in the firebox until the draft is felt, then lighting the fire.

The Regency manual adds that a new installation can be harder to start for the first few days, and that the draft increases as the firebrick and the masonry flue dry out. Keep the air fully open for start-up and build a small, hot fire before adding bigger wood.

A House That Pulls Air the Wrong Way

The fire needs air from somewhere. The Superior Pro Series manual names a range hood, exhaust fans, a clothes dryer and a furnace among the appliances that can put a tight house under negative pressure, pulling air down the chimney against the smoke. Its test is simple: turn the blowers off and open a nearby window. If the smoking stops, the house is short of air.

The Regency manual names another culprit: a second fireplace in the home. A burning insert can pull air down the other chimney, and the manual's fix is a window opened slightly near the insert.

Wet Wood

Wet or green wood smolders instead of burning, and smolder makes smoke. The Regency manual does not recommend it; if it must be burned, the draft control should stay fully open until the moisture has been driven off. The real fix is dry, split wood that has seasoned under a cover on top. Loose paper, cardboard and trash cause smoke spillage too, the manual says, so keep them out of the firebox.

What You Can Check, and What You Should Not

Safe checks: the wood, the door routine, a window test with exhaust fans off, and, with the insert cold, whether the baffles sit flat and locked against the back wall. Do not pull the insert, climb the roof or seal joints with anything not named in the manual. If smoke appears behind the faceplate or keeps coming through the seams, stop using the insert until it is checked.

Our Visit

We look at the insert, the baffles and gasket, the connection to the liner, the throat behind the faceplate and the chimney top, then show you what we found. Fixes run from a gasket and latch adjustment to a full liner on our fireplace insert installation work, each written up in an estimate after a free inspection.

Smoke problems get a patient look from our experienced crew. We are a family-owned local outfit, Proudly American, and we would rather find the cause than sell a part. Spring Hill homeowners hear a straight answer about the smoke from a Proudly American family business before any money is spent.