Your chimney’s odd behavior, smoke backing up, strange smells, or soot on walls, often has simple fixes. But Denver’s dry winters and old masonry hide dangers like hidden cracks or blocked flues. Start with these safe checks, then call a pro when you see warning signs like excessive creosote or rusted damper hardware. Never ignore smoke that won’t draft or a cold fireplace when the fire’s burning hot.
Myth: ‘If my chimney’s cold, it’s just drafty, no big deal’
A cold chimney when your fire’s roaring is never ‘just drafty’ in Denver’s climate. Cold air rushing down can pull unburned gases into your home, creating carbon monoxide risks. First, check for obvious blockages: Look up the chimney from your roof (safely with binoculars) for debris like leaves or bird nests. If you see anything, do not climb or poke it, this is a job for a chimney sweep. Next, inspect the damper: Open it fully and listen for airflow. If it’s stuck or rusted, that’s a red flag. For gas fireplaces, ensure the vent connector isn’t crushed or disconnected /compare/wood-vs-gas-fireplace/. If the problem persists, the flue may need relining or repair /compare/repair-vs-replace-chimney/. More on this in the service list.
What Most Denver Homeowners Get Wrong: ‘A little soot on the fireplace is normal’
Soot is normal, but excessive black soot or glossy creosote on the fireplace walls or glass means incomplete combustion, a fire hazard. Denver’s dry air and older wood stoves worsen this. Safely check your glass doors for thick creosote buildup (it should be light gray, not black or tar-like). If you see heavy deposits, schedule a chimney sweep before your next fire, creosote is highly flammable. For masonry chimneys, inspect the interior with a flashlight (if accessible) for soot higher than 1/8 inch thick. If DIY checks reveal more than light soot, call a professional /areas/aurora-co/, they’ll assess if your chimney needs cleaning or repairs to improve draft. Worth a look: request a free estimate / contact us page.
Myth: "I Can Spot Chimney Problems Without a Pro: Here’s How to Check (Without Getting Burned)"
1. Exterior Inspection: Walk around your home and look for cracks in the masonry, missing mortar, or rusted hardware. Denver’s freeze-thaw cycles worsen these over time. If you spot large cracks (bigger than a pencil), do not attempt repairs yourself, this requires a mason and structural assessment. 2. Damper Test: Open the damper fully and shine a flashlight up the flue. If you see daylight at the top, the flue may be cracked (a serious risk). 3. Start with a fire test: Burn a small amount of wood and observe how the smoke moves up the flue. If it backs into the room or smells like gas, your chimney is blocked or improperly sized for your fireplace. 4. Carbon Monoxide Detector: If your CO detector alarms during fireplace use, extinguish the fire immediately, open windows, and call a chimney professional, this is a life-threatening emergency. Never ignore this. There is more in about our team and credentials.
Red Flags: 5 Signs Your Chimney Is Sending You a Silent Warning (Before It’s Too Late)
These are never DIY fixes, stop using your fireplace and call a licensed chimney sweep immediately: 1. Smoke or fumes in the room when the damper is open and fire is burning. 2. Orange or yellow flames (not the usual blue), this means poor combustion and high creosote risk. 3. Visible cracks in the chimney crown or bricks, especially if water is leaking inside. 4. Creature intruders: If you hear scratching inside the chimney or find droppings near the fireplace, animals may have taken up residence. 5. Rust on the damper or smoke chamber, or a damper that won’t stay open/closed. Denver’s humidity accelerates rust, which can lead to structural failures. If you see any of these, do not use your fireplace until a professional inspects it /services/. For the specifics, see where we work page.
When to Call Lizard Chimney Inc: Because Some Problems Aren’t Fixable at Home
Denver’s chimneys hide dangers behind simple symptoms. Call us if: Your chimney hasn’t been swept in over a year (creosote buildup accelerates in dry climates like ours). You notice water stains on ceilings or walls near the fireplace, this means a leaky chimney crown or flashing, which can rot wood and damage your home’s structure. Your fireplace smells like gas or chemicals when lit, even with a new log. You hear loud roaring or popping sounds from the chimney (could indicate a blocked flue or collapsing liner). We offer Level 2 inspections (which check inside the flue) to catch these issues early /blog/denver-chimney-inspections-levels-1-3-explained/. Our team serves Denver, Aurora, Lakewood, and surrounding areas, schedule your inspection before winter sets in /contact/.
Frequently Asked Questions
My Denver home’s chimney worked fine last winter, but now smoke backs up into the room. What’s the first thing I should check?
Start by checking if the damper is fully open and not stuck. Next, inspect the top of the chimney for debris or animal nests. Denver’s wind can push leaves or twigs down the flue. If the damper moves freely and the chimney looks clear, the issue might be a blocked or collapsed liner, which requires professional cleaning and inspection. Never burn fires with a blocked chimney, this creates deadly carbon monoxide risks. If smoke still backs up after clearing debris, call a chimney sweep to assess the flue’s condition /areas/lakewood-co/.
I found a small crack in the chimney crown near my Westminster home. Can I patch it myself with fireplace cement?
No, patching a chimney crown yourself is dangerous. Denver’s freeze-thaw cycles will cause the patch to fail quickly, leading to water damage and structural issues. A small crack can turn into a major leak, rotting your roof and damaging the flue. Always hire a licensed chimney professional to repair crowns and flashing. We use high-temperature, waterproof mortars and inspect for hidden damage during repairs /blog/denver-chimney-crown-chase-cover-repair/. A quick fix now could cost you thousands in water damage later.
My gas fireplace in Thornton smells like sulfur when I turn it on. Is this normal, or should I call someone?
That ‘rotten egg’ stink isn’t just weird, it’s deadly. A sulfur smell from your gas fireplace means the burn isn’t clean, which could point to a blocked vent, a cracked heat exchanger, or even a gas line leak. Turn off the fireplace right away, crack open windows, and call a professional /areas/thornton-co/. Denver’s older homes sometimes hide aging gas lines, don’t wait for a CO detector to scream before acting. This isn’t just a nuisance; it’s a fire and poisoning risk.