Start with what you notice
Use these as clues, not a diagnosis. Any smell of burning plastic, hot wiring or gas is a safety issue first.
- IfSmell of rotten eggs or sulfurThenLeave the home and call your gas utility or 911 from outside. Do not switch lights or appliances on or off.
- IfSmell of hot plastic or burning wiring, or a warm outletThenTurn off the circuit if safe, leave, and call 911. Have an electrician inspect before using that circuit.
- IfStale, sweet-sour ashtray smell that is strongest in closets, cabinets and fabricsThenTobacco residue is the likely source.
- IfCampfire or creosote smell near the hearth, worse when kitchen or bath fans runThenLikely fireplace downdraft; have the chimney inspected and swept.
- IfSmoky haze outdoors and indoors at the same time, on dry summer daysThenLikely wildfire smoke; it fades as outdoor air clears, especially with good filtration.
- IfFresh cigarette or cannabis smoke appearing at certain times of dayThenLikely drift from a neighbor or common area, not old residue.
How the sources usually differ
- Source
- Old tobacco residue
- Character of the smell
- Stale, sour, sometimes sweet
- Timing
- Constant; worse when warm or closed up
- Visible signs
- Yellow tint, sticky film, tan filter
- Source
- Fireplace or chimney
- Character of the smell
- Campfire, tar, creosote
- Timing
- Worse in humid weather or when exhaust fans run
- Visible signs
- Soot near the firebox opening, black streaks on brick
- Source
- Wildfire smoke
- Character of the smell
- Woodsmoke, sometimes acrid
- Timing
- Comes and goes with outdoor air quality
- Visible signs
- Haze outdoors, gray dust on sills
- Source
- Neighbor's smoking
- Character of the smell
- Fresh smoke
- Timing
- Repeats at the same times
- Visible signs
- None in your unit at first
Why fireplace odor fools people
Many of the older brick houses in Country Club, Belcaro and Congress Park have wood-burning fireplaces that have not been used much in years. When a modern kitchen hood or bath fan pulls air out of a tightly closed house, the house will draw replacement air from wherever it can, and an open or leaky damper is an easy path. Air coming down the chimney carries creosote odor into the living room, and it can smell a lot like stale smoke.
The giveaway is location and timing: the smell is strongest at the hearth and shows up when exhaust fans run or on humid days. Tobacco residue, by contrast, is spread across ceilings, fabrics and closets and does not care whether the range hood is on. A chimney sweep can tell you whether the flue needs cleaning, whether the damper seals, and whether a top-sealing damper or other fix makes sense.
Wildfire smoke is a different story. It comes from outdoors on bad air days, and a good furnace filter, closed windows and a portable air cleaner help. It leaves much less lasting residue than years of indoor cigarettes.
General information for Cherry Creek, not a quote or professional advice. In an emergency, call 911.