Category: Fireplace Tips

There are three common gas hearth appliances and they are not interchangeable. A gas log set is a burner and ceramic logs dropped into an existing wood fireplace. An insert is a sealed firebox slid into that same masonry opening with its own liner. A built-in gas fireplace is a factory unit with no masonry behind it at all. Which one you own determines how it vents, what goes wrong with it, and what service it needs.

How to tell them apart in about a minute

Look past the glass and work through this:

• Do you see real brick or firebrick behind the logs, and is the chimney masonry? If the logs sit loose in a brick firebox and you can see the damper above them, that is a gas log set in a converted wood fireplace.
• Is there a sealed glass front you cannot open, fitted into a masonry opening, with a metal surround covering the gap around it? That is a gas insert. There is a liner running up the old chimney, usually two pipes, one bringing air in and one carrying exhaust out.
• Is the whole unit metal, with no masonry anywhere, often on an interior wall or a wall with siding directly behind it? That is a built-in direct-vent gas fireplace, and it most likely vents horizontally out through the wall rather than up a chimney.

If the glass is fixed and sealed all the way around, you almost certainly have direct venting. If there is an open front with a mesh curtain, you have a vented log set or a B-vent unit, and the damper position matters.

Why the distinction is a safety matter, not a trivia question

Each configuration fails differently.

A vented gas log set requires the damper to stay open whenever it runs, which is why installers fit a damper clamp – a stop that prevents the damper from ever fully closing. If someone has removed that clamp, or the damper has been shut, exhaust has nowhere to go. It also means the flue is open to the outdoors year-round, so the fireplace is a permanent hole in the house. And crucially, a masonry flue sized for a wood fire is often oversized for the much cooler exhaust of gas, which lets that exhaust condense on the way up. Gas exhaust is wet and acidic, and it degrades clay tile liners and mortar quietly for years.

A gas insert depends entirely on the liner installed with it. If that liner is damaged, disconnected at the top, or was never sized correctly, the appliance is venting into the chimney chase rather than outside. These units are sealed from the room, which is a real safety advantage – but it also means you will not smell a problem developing.

A direct-vent fireplace fails at the termination. The vent cap outside gets blocked by a bird nest, by ice, by dryer lint drifting over from a nearby vent, or by landscaping that has grown up around it over five summers. The unit will then shut itself down on a safety switch, which is the system working – but people often reset it repeatedly rather than clearing the blockage.

Across all three, the parts that quietly stop working are the same: thermocouples and thermopiles that weaken with age, pilot assemblies that clog with dust and spider webbing over the summer, and gas valves that lose the ability to hold a stable flame. A failing gas valve shows up as slow lighting, delayed ignition with an audible thump, or a burner that will not stay lit. Replacing one is work for someone qualified on gas – it is not a parts swap to attempt from a video.

What annual service actually covers

Gas hearth appliances need a yearly look, same as wood. The visit covers the burner and its ports, the pilot assembly, thermocouple and thermopile output, the gas valve and its connections, the glass gasket on sealed units, the venting and its termination, and log or media placement – which matters more than it sounds, because logs shifted out of position cause sooting and can block burner ports.

Soot is the clearest warning sign. Gas burns clean. Black on the glass or on the logs means incomplete combustion, and that is worth a call rather than a wipe with glass cleaner. So is a smell of gas, a pilot that will not hold, or a unit that has started cycling on and off.

Service is starting at $159. If yours vents into a masonry chimney, a chimney inspection is worth pairing with it, because the condition of the flue is a large part of whether the appliance is venting properly. The full list is on our pricing page.

Book gas fireplace service in Naperville

We cover Naperville and the surrounding area seven days a week, 7am to 9pm, insured and bonded. If you are not certain which of the three you have, call and describe it – we can usually sort it out over the phone and bring the right parts. See gas fireplace service for what the visit includes.

Call (630) 451-4178

Written by Josh Amber, co-owner of Ember Chimney Sweepers, Oswego IL. Published October 23, 2026.

An open masonry fireplace sends most of its heat up the flue, and a few fixable faults make that far worse. If you are burning through a rack of wood in a weekend, the usual culprits are a damper that no longer seals, wood that is not actually dry, and a firebox pulling heated room air up the chimney all evening.

Start with the wood, because it is the cheapest thing to fix

Wood above roughly 20 percent moisture spends the first part of every fire boiling water instead of making heat. You paid for that water by the rack and it leaves as steam. The fire runs cool, the flames look lazy and yellow, and the smoke is dense – which also means creosote accumulating in the flue at a much faster rate.

The tells are easy to read. Seasoned wood is lighter than it looks, the ends are checked and cracked, the bark has loosened, and two pieces knocked together ring rather than thud. Wood cut and split this summer is not ready this winter. Oak wants two years; ash and cherry can be ready in one. Stack it off the ground, single row, ends open to the wind, top covered and sides open.

A moisture meter costs about fifteen dollars and settles the argument permanently. Split a piece and read the fresh face, not the weathered outside.

Then look at what the fireplace does when there is no fire in it

An open fireplace with the damper up is a hole in your house. When the fire is out and the damper is open, heated air leaves through it continuously and your furnace replaces it. That is the single largest source of waste in most fireplaces, and it happens when nobody is thinking about the fireplace at all.

Old throat dampers rarely help as much as people assume. A cast-iron plate sitting in a masonry throat warps with heat cycles, collects soot and rust on its seat, and eventually closes to within a quarter inch of shut instead of actually sealing. You can check yours from below with a flashlight and a mirror: close it and look for daylight.

A top-sealing damper mounts at the crown with a silicone gasket and seals against the weather rather than against a rusted iron frame. It also keeps rain, snow and animals out of the flue, which the throat damper never did. Installed, one is starting at $239 – see chimney caps and dampers and the pricing page for the current figures.

The way you build the fire matters more than people expect

Three things are worth changing tonight:

• Build it top-down. Large splits on the bottom, medium above them, kindling and tinder on top. It lights from the top and burns downward, which warms the flue quickly, establishes draft sooner and produces noticeably less smoke through the first twenty minutes.
• Warm the flue first. On a cold morning the air in the chimney is dense and sitting still. Hold a rolled, lit sheet of newspaper up near the damper for thirty seconds before you light the fire. That is often the difference between a fire that takes and a fire that smokes.
• Burn fewer, hotter fires. A hot fire burns its own smoke. A smoldering, damped-down fire kept going all evening burns more wood per unit of heat and coats the flue while it does it.

The bigger structural question is whether an open fireplace is the right appliance at all. If you are burning for heat rather than for the look of it, an insert changes the arithmetic completely by closing the firebox and drawing combustion air from a controlled source. Plenty of Yorkville homes have made that switch, and it needs a correctly sized liner to do it safely – a conversation for an inspection, not a weekend project.

Have the damper and flue checked

If you are not sure whether your damper seals, we can tell you in about five minutes, and we will check the flue size against the fireplace opening while we are there. A sweeping is starting at $119. We are out seven days a week, 7am to 9pm, insured and bonded.

Call (630) 451-4178

Written by Josh Amber, co-owner of Ember Chimney Sweepers, Oswego IL. Published October 21, 2026.

Only dry, seasoned firewood and plain newspaper or kindling belong in a wood-burning fireplace. Five things cause most of the trouble we see: cardboard and wrapping paper, painted or pressure-treated lumber, plywood and particleboard, evergreen boughs, and any kind of liquid accelerant. Each one fails in a different way, which is why the list is worth understanding rather than memorizing.

Cardboard, pizza boxes and wrapping paper

These burn fast and light, and that is the problem. They flare up in seconds, create a strong updraft, and carry burning fragments up the flue before they have finished burning. Those fragments can land on the roof, in gutters full of leaves, or on the ground beside the house. Glossy wrapping paper and printed boxes also carry inks and coatings that leave residue in the flue.

After holiday gatherings in particular, recycle the boxes and paper instead. A handful of plain newspaper to start a fire is fine; a garbage bag of wrapping is not.

Painted, stained or pressure-treated lumber

Scrap wood from a deck, fence or remodel looks like free firewood and is not. Pressure-treated lumber is soaked in chemical preservatives, and older treated wood in particular was made with arsenic-based compounds that are released in the smoke and concentrated in the ash. Paint and stain, especially on older boards, can contain compounds you do not want to breathe or spread on a garden.

Plywood, particleboard and MDF have a different problem: they are held together with resins and glues that produce acrid smoke and heavy deposits. None of these belong in a fireplace, even in small amounts.

Evergreen boughs and the Christmas tree

A dried-out Christmas tree or a bundle of pine and spruce trimmings burns with sudden, intense flare-ups from the resin-rich needles. That surge of heat and sparks is the kind of fire that can overwhelm a screen and ignite existing creosote in the flue. Green evergreen wood cut in the yard has the opposite issue, too much moisture and pitch, which builds creosote quickly.

Let a tree go out with your municipal yard waste collection. Seasoned hardwood, split and dried for at least a season, is what the fireplace is built for, and our earlier guide on how to tell if firewood is actually seasoned covers how to check.

Lighter fluid, gasoline and other accelerants

Never use them indoors. Liquid accelerants vaporize before they burn, and the vapor can fill the firebox and ignite all at once, pushing flame out into the room. A slow-starting fire is almost always a draft, damper or wet-wood problem, and our chimney DIY guide covers the safe things to check. Commercial fire starters sold for fireplaces are fine when used as directed.

Ashes: the part people forget

Ashes that look cold can hold live embers for days. Shovel them into a metal container with a tight metal lid, set it outside on a non-combustible surface well away from the house, deck and garage, and never put ashes in a paper bag, a plastic bin or a trash can.

Many of the homes we service in Boulder Hill have original masonry fireplaces that have seen decades of use, and what gets burned in them shows up plainly when we sweep. If yours has had a season of questionable fuel, a chimney sweep clears the residue, and our rates are published on the pricing page.

Start the season with a clean flue

Ember Chimney Sweepers is owned by Josh Amber and his brother Jack, born and raised in Oswego, with 35 years of combined experience. We are insured and bonded and take calls every day of the week from 7am to 9pm.

Call (630) 451-4178

Written by Josh Amber, co-owner of Ember Chimney Sweepers, Oswego IL. Published October 12, 2026.

Firewood is ready to burn at 20 percent moisture content or below. Below that it burns hot and clean; above it, the fire spends its energy boiling off water, cooling the flue and condensing far more creosote onto the walls.

Four checks you can do without a meter

Weight is the most reliable feel test. Seasoned wood is dramatically lighter than green wood of the same species and size, because a large share of its original weight was water.

End-grain cracks radiating outward from the centre appear as wood dries and shrinks. Their presence is a good sign, though wood can crack on the surface while remaining wet inside, so do not rely on this alone.

Bark on properly seasoned wood is loose and often falls away on handling. Sound is the quickest test of all: knock two pieces together. Seasoned wood produces a sharp hollow crack. Green wood gives a dull thud.

A moisture meter costs very little and removes all guesswork. Split a piece and test the freshly exposed inner face, not the outside, which dries first and reads misleadingly low.

How long wood actually needs

Longer than most people expect, and the seller’s word is not evidence. Softwoods may be ready in six months. Most hardwoods need a full year. Dense species such as oak commonly need eighteen months to two years to come down below 20 percent.

Stacking matters as much as time. Split the wood first, because rounds dry extremely slowly. Keep the stack off the ground, cover the top only, and leave the sides open to airflow. A tarp wrapped over the whole pile traps moisture and prevents seasoning entirely, which is one of the most common mistakes we see.

Wood delivered as seasoned is frequently nothing of the sort. If you buy in, buy a year ahead and season it yourself.

Why this matters more in Sugar Grove

Households on larger lots here burn considerably more wood than dense suburban subdivisions, often using a stove or insert as a genuine heat source through the whole winter rather than for occasional evening fires.

Real heating use with wet wood is the fastest route to stage-three glazed creosote, the hard tarry deposit that forms when soft soot bakes repeatedly. It is highly flammable, it takes far longer to remove than annual soot, and it costs more to deal with. Burning dry wood and keeping to an annual sweep is both the safer and the cheaper path.

Talk to a local chimney pro

If you heat with wood in Sugar Grove or the surrounding Kane County countryside, book your sweep before heating season rather than during it.

Call (630) 451-4178

Written by Josh Amber, co-owner of Ember Chimney Sweepers, Oswego IL. Published September 25, 2026.

Black sooty film on gas fireplace glass almost always means the ceramic logs are out of position, causing flame to strike the log instead of burning through its designed channel. That is incomplete combustion, and it produces carbon monoxide as well as soot.

White film is normal, black soot is not

There are two different deposits and they mean very different things. A light white or grey haze is sulfur residue from normal combustion, it is expected, and it cleans off with the correct fireplace glass cleaner.

Black, oily soot is not normal. It is unburned carbon, and it means the fuel is not combusting completely. Whatever is causing the glass to blacken is also producing carbon monoxide, which is the part that actually matters.

Ceramic logs are engineered, not decorative

This is the cause we correct more than any other in Naperville. Gas logs are designed to sit in exact positions so that flame travels through specific channels between and around them. Move one half an inch and flame impinges directly on ceramic, which chills it below the temperature needed for complete combustion.

Logs get moved constantly and innocently: during cleaning, when someone vacuums the firebox, or because a homeowner thought the arrangement looked better a different way. Once out of position they are almost never put back correctly by eye, because the correct positions are specified by the manufacturer, not by appearance.

The other causes, and the right response

If log placement is correct, the next suspects are burner ports clogged with dust, pet hair, or spider webs, which is extremely common in units used only a few weeks a year; insufficient combustion air; or a venting restriction preventing the unit from drawing properly.

What you should do: stop using the fireplace until it has been looked at, confirm your carbon monoxide alarm is working, and book a gas fireplace service. What you should not do is simply clean the glass and carry on, because the soot is a symptom rather than the problem.

We reposition logs to manufacturer specification, clean the burner and pilot assembly, test millivolt output, verify venting, and leak-test the gas connections.

Talk to a local chimney pro

Naperville homes often have several fireplaces and the gas units are usually the neglected ones. If yours is sooting, book it before the weather turns. We cover all of Naperville seven days a week.

Call (630) 451-4178

Written by Josh Amber, co-owner of Ember Chimney Sweepers, Oswego IL. Published September 22, 2026.