5 Signs Your Fireplace Needs Repair
A fireplace that needs repair usually tells you so. Odd noises, smoke or a smell in the room, cracks in the firebox or chimney, rust on the metal parts and a build-up of black creosote are the five signs your fireplace needs repair that we see most in Downers Grove homes. None of them fixes itself, and every one is simpler and cheaper to deal with in September than in January. Here is what each sign usually means on a wood fireplace and on a gas one, and what to do about it.
1. Unusual noises
A wood fire pops and crackles. That is the wood, and it is normal. What is not normal is a steady hiss, which is wet wood boiling off its moisture, a bang or clank from the metal parts, or a loud roaring or rumbling from inside the chimney while the fire is lit. Roaring means a chimney fire. Get everyone out and call 911, and have the chimney inspected before it is used again, because a chimney fire cracks flue tiles even when it looks as though nothing happened.
On a gas fireplace, listen for a small whump when the burner lights. That is delayed ignition: gas collects for a second or two before it catches, usually because the burner ports or the pilot are dirty. A rattle or whine when the blower runs is the fan. Both are service items, and delayed ignition should not wait.
2. Poor draft or smoke backing up
A healthy fireplace pulls smoke straight up the flue. If smoke or a smoky smell drifts into the room, first check that the damper, the metal plate in the throat of the chimney, is fully open, and that no kitchen or bathroom fan is running. If that is not it, the flue is narrowed by creosote, blocked by a nest or leaves, or the flue tiles have shifted. Smoke in the house is a health problem as well as a nuisance, so stop using the fireplace until the chimney has been swept and inspected.
A direct-vent gas fireplace does not use the chimney, but it can still smell. A burnt-dust smell for the first few minutes of the season is normal. A smell that carries on after that, or a film of soot on the glass, means the unit is due for a service.
3. Cracks in the firebox or chimney
Look inside the firebox, the chamber the fire sits in, for cracked or crumbling firebrick and mortar joints, and outside for cracked brick, missing mortar or a cracked concrete crown on top of the chimney. Hairline cracks in mortar are routine and are repaired with heat-resistant fireplace mortar. Wider cracks, loose bricks or gaps you could slide a coin into let heat and hot gases reach the wood framing around the fireplace, and let water into the masonry, where a Chicago freeze-thaw winter turns a small crack into a big one. Do not use the fireplace until a wide crack has been inspected.
In a factory-built or gas fireplace, the parts that crack are the heat-resistant panels lining the box and the glass. Cracked panels are replaced. A gas unit with cracked glass should not be run at all until the glass has been replaced.
4. Rust or corrosion
Rust means water, and water is the enemy of a chimney. A rusty damper, rust streaks in the firebox, flaking metal on the chimney cap or a corroded vent termination all say that rain or condensation is getting where it should not. The usual sources are a missing or damaged chimney cap, a cracked crown, failed flashing where the chimney meets the roof, and, on a gas appliance vented into an old masonry chimney, moisture in the exhaust condensing inside a flue that is too large for it. Find the source and fix it first, then deal with the rusted part. A rusted damper often needs replacing; a rusted cap always does.
5. Excessive creosote build-up
Creosote is the black, tar-like residue that wood smoke leaves inside the flue as it cools. A thin dusty layer between sweeps is normal. Thick flakes, a crust or a shiny glaze on the flue walls or the back of the firebox is a fire waiting for a spark, and a strong smoky smell in the house on a humid summer day is the same warning by nose. Burning wet wood and letting fires smolder overnight both build creosote faster.
The fix is a professional sweep. Glazed creosote in particular needs tools that a hardware-store brush kit does not have. Our chimney cleaning and repair service sweeps the flue, inspects the whole chimney and gives you a written note of what it found and what, if anything, needs repair.
The same five signs on wood and gas
| Sign | Wood-burning fireplace | Gas fireplace or log set |
|---|---|---|
| Noises | Hissing is wet wood; roaring in the chimney is a chimney fire | A whump at ignition is a dirty burner or pilot; a rattle is the blower |
| Smoke or smell | Damper, cold flue, or a blocked or dirty chimney | Burnt dust is normal for a few minutes; a lasting smell or soot means a service |
| Cracks | Firebrick, mortar joints, chimney crown and brick | Lining panels and the glass; never run with cracked glass |
| Rust | Damper, cap and flashing letting water in | Burner, logs and vent cap; moisture from a flue that is too big |
| Creosote | Thick flakes or glaze in the flue | None from gas, but soot on the logs and glass is the equivalent warning |
What to do when your fireplace needs repair
Stop using it if the sign is smoke in the room, a wide crack, cracked glass, a roaring chimney or a smell of gas. For a gas smell, leave the house, call your gas utility from outside, then call us. For the other signs, use the fireplace with care and book an inspection.
Take a few photos: the sign itself, the whole fireplace and the rating label behind the louvers or control door on a gas unit. Send them with your service appointment request and we can often tell you before we arrive what the repair is likely to involve. On the visit we look at the whole system, not just the symptom, and quote any repair in writing before we start. Even with none of these signs, a fireplace that has not been inspected in more than a year is due.
If this is the third repair on an old unit, it may be time to talk about a replacement. A modern gas insert or wood insert is a different thing from what was built into a house in the 1970s, and the showroom has them on display so you can see the size and the finish in person. For the fixes you can do yourself, see our guide to common fireplace problems and how to fix them.
Common questions
Should I stop using the fireplace if I notice one of these signs?
Yes for smoke in the room, a wide crack, cracked glass, a roaring chimney or any smell of gas. For a new noise or surface rust, book an inspection before the next fire; for heavy or glazed creosote, stop using the fireplace until it has been swept and inspected.
Is a small crack in the firebox dangerous?
A hairline crack in a mortar joint is routine and is filled with fireplace mortar. A crack you can fit a coin into, a loose brick or a cracked panel needs an inspection before the next fire.
What does rust in a fireplace mean?
Water is getting in, usually through a missing cap, a cracked crown or failed flashing. Fix the source first or the new part will rust the same way.
Do gas fireplaces show these signs too?
Yes, in their own way: delayed ignition instead of hissing, soot instead of creosote, cracked glass or panels instead of cracked brick. A gas unit needs a yearly service just as a wood fireplace needs a yearly sweep.
Can I remove creosote myself?
A brush kit will knock loose soot off a straight flue, but it cannot remove glazed creosote or tell you that a flue tile has cracked. Have the chimney swept and inspected once a year, whatever you do in between.
Talk it through in the showroom
A Fireplace Store and More is at 1202-B 75th Street in Downers Grove, open seven days. Bring a photo of the wall or the opening, or just the question. We size it, quote it in writing and install it with our own team. Book a showroom or in-home visit, ask for a written estimate, or call (630) 241-1919.