Fireplaces and flues
Fireplace inserts, and how to tell whether yours has a full liner or none
We clean wood-burning fireplace inserts around Portland by sweeping the liner from the top and the firebox from below; when an insert was slid into an open flue with no liner, we pull it, inspect the chimney and say what it needs.
Updated
What a fireplace insert is and how it vents
A fireplace insert is a wood stove built to slide into the opening of an existing masonry fireplace, with a steel surround panel closing the gap to the brick and, on newer units, a blower that pushes room air around the firebox.
It should vent through a stainless liner connected to the insert collar and run to the top of the chimney, with a plate sealing the old damper opening around it. The insert turns a fireplace that sent its heat up the flue into a closed appliance that puts it in the room.
That makes it a natural upgrade for the brick fireplaces in Portland's pre-1960 houses, close to half the city's housing by census count. Some older inserts went in with no liner at all; the trade calls those slammers, and they are the first thing we sort out.
How to tell what you have
Here is how to tell an insert from a freestanding stove and from a prefab box.
- A steel or cast iron box filling the fireplace opening, with a flat surround panel covering the brick around it.
- Louvers or a grille at the top and bottom of the surround, and a fan switch or thermostat knob along the lower edge.
- At the chimney top, a round stainless cap sized to a liner sitting on the old clay tile, or a flat plate with a pipe through it.
What you will find in Portland homes
These are the insert setups we meet in Portland fireplaces, oldest first.
| Type or model | Era | Notes |
|---|---|---|
| Slammer insert with no liner | Older installs | Pushed into the opening to vent into the open flue; creosote piles up on the smoke shelf where no brush reaches, so the unit comes out for any real cleaning, and without a DEQ or EPA label it falls under the removal law. |
| Direct-connect insert | Later installs | A short stainless stub from the collar up through the damper to the first tile, with the rest of the flue bare and oversized; the stub joint is where the creosote collects. |
| Full-liner insert | Current installs | A stainless liner from the collar to a cap at the top, usually insulated, with a block-off plate at the damper; swept from the roof without moving the insert, the setup every insert should have. |
| Hybrid and catalytic inserts | current | Low-emission units with a combustor behind a bypass or a baffle with secondary air tubes; a plugged combustor is why a newer insert smokes or will not come up to temperature. |
What goes wrong and what fixes it
Insert trouble usually starts with the liner, or the lack of one, and every problem below names the service that fixes it.
-
Creosote in the liner and on the baffle, with glass that blacks over in a day
Liner swept from the top into the firebox, baffle lifted, collar and blower cavity vacuumed, photos before and after Wood Stove and Insert Sweep, from $279
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An insert venting into the open flue with no liner, or a stub that stops at the first tile
Insert pulled, smoke shelf and flue cleaned and inspected, then an insulated stainless liner from the collar to a new cap Chimney Liner Installation, from $1999
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No record of what is behind the surround, or smoke staining above the mantel
A Level 2 scan of the flue with the camera, the label and listing read, and the connection checked with the surround off Chimney Inspection, from $129
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Third-degree glaze on the liner from years of low, slow overnight burns
Rotary cleaning or a chemical treatment ahead of it, and a change in how the insert is run Creosote Removal, from $449
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A damaged smoke chamber or cracked firebrick found once an insert is pulled
Chamber parged smooth and brick reset before the insert goes back Smoke Chamber and Firebox Repair, from $299
How a fireplace insert is cleaned without pulling it, and when it has to come out
With a full liner the insert stays put: we sweep from the roof down the liner into the firebox, lift the baffle and vacuum the collar, much like a stove sweep.
Without a liner the insert comes out: two people slide it forward onto boards over the hearth, the smoke shelf and the open flue get cleaned and photographed, and the chimney gets a proper look before anything goes back. The pull is what finds the problems.
Why an insert with no liner is the first thing to fix
An insert dumping smoke into an open flue cools it, coats the smoke shelf and the brick with creosote no brush reaches from below, and spills carbon monoxide back into the room when the draft falters.
The fix is an insulated stainless liner sized to the insert collar, run to a cap at the top with a block-off plate at the damper, under a permit. We do the pull, the cleaning and the liner; keep a carbon monoxide alarm on that floor meanwhile and leave the insert cold until it is lined.
Pulling an uncertified insert for a Portland home sale
Oregon's home-sale removal law covers fireplace inserts as well as freestanding stoves, so an uncertified insert must come out and be destroyed when the house changes hands, while the open masonry fireplace it sits in is exempt.
The label is on the back or the side of the insert body, so the surround comes off and the unit slides forward before anyone can read it. We do that on a real estate inspection, photograph the plate or its absence, and camera the flue behind it, since the chimney stays with the house.
If the insert goes, the fireplace is back to an open hearth with whatever the years of unlined venting left behind. A sweep, a Level 2 inspection and usually a liner come next; a new labeled insert, if the next owner wants one, goes in through a hearth dealer and a permit.
An insert whose glass turns black in a single evening, that smokes when the door opens, or that has had a chimney fire stays unlit until it is inspected. For a chimney fire in progress, leave the house and call 911 first, and touch nothing on the stove.
Fireplace insert questions
Can a fireplace insert be cleaned without removing it?
Yes when it has a full stainless liner connected to its collar. We sweep from the top straight down into the insert and vacuum the collar through the firebox with the baffle lifted. An insert with no liner or only a short stub has to come out, because the creosote collects on the smoke shelf behind it.
How can I tell whether my fireplace insert has a liner?
Look at the chimney top first. A round stainless cap on a pipe inside the old tile means a liner; a bare tile or a big masonry cap usually means none. Inside, a flashlight up past the insert's top edge shows a stainless pipe or an open brick void. We confirm it with the camera on a first visit.
Does Oregon's home-sale rule apply to a wood fireplace insert?
Yes. The removal law names fireplace inserts alongside wood stoves, so an insert with no DEQ or EPA label must be pulled and destroyed when the home sells, by the seller before closing or by the buyer within thirty days if they agree in writing. The masonry fireplace it sat in is exempt.
Why has the blower on my fireplace insert gone quiet or started rattling?
Dust, pet hair and ash packed into the fan cage, or a motor at the end of its life. The blower sits in the cavity under the firebox and only gets cleaned when someone pulls the lower louver, so we do it on every sweep. A silent fan on a hot stove may be a failed snap switch, a simple part.
Is it worth putting an insert into an old unlined brick fireplace?
Often yes, because the liner that comes with a proper insert installation also solves the unlined flue. The insert vents through its own insulated stainless pipe from collar to cap, so the old brick never sees exhaust again. The chimney needs a Level 2 inspection first, and a leaning or spalled stack needs masonry work before anything goes in.
Related pages
Fireplace insert calls near you
Fireplace insert work has taken us to Beaverton, Eastmoreland and Reed, Hillsboro and the rest of the metro, and the posted price is the same at every address.
Other fireplace and flue types
Ready to book a sweep?
Call with what the fireplace is doing, or text a photo of the opening and one of the chimney top, and we will name the service and its posted price before we come out.