Why does smoke come back into my room when I light a fire?
Four common causes: cold flue (priming issue), incorrect smoke chamber geometry (the angled walls above the firebox aren't shaped right), failed damper, or negative house pressure (modern tight homes pulling air down the flue). Diagnosis identifies which one — fix depends on it.
How do you diagnose draft problems?
Smoke pencils to visualize airflow. Digital draft meters to measure pressure differential. Camera scope of the smoke chamber to check geometry. Flue-size calculation against firebox-opening size. House-pressure measurement during fireplace operation. Real data, not guesses.
What's a smoke chamber and why does it matter?
The smoke chamber is the angled, transitional space above your firebox — between the damper and the flue. NFPA 211 requires specific shape and slope for proper draft. Most chambers built before 1990 are out of code, and that's often why your fireplace smokes.
Can a damper cause draft problems?
Absolutely. A throat damper that doesn't open all the way restricts draft. One that doesn't close at all lets cold downdraft into the house. Rusted, stuck, or warped dampers are common culprits — and usually fixable for a few hundred dollars.
What is a top-sealing damper?
A spring-loaded sealing cap installed at the top of the flue, controlled by a chain reaching down to the firebox. Replaces or supplements a failed throat damper. Seals airtight when not in use (saves heat). Eliminates downdraft and most cold-flue priming issues.
How long does draft diagnosis take?
Diagnosis appointment: 60–90 minutes including smoke testing, camera scope, and measurements. Most repairs can be quoted on the same visit. Damper repair: 1–2 hours. Smoke chamber parging: 4–6 hours. Top-sealing damper install: 1–2 hours.
What does draft diagnosis cost?
Diagnosis: $150–$250 (often credited toward repair if booked). Damper repair: $300–$800. Smoke chamber parging: $1,200–$2,800. Top-sealing damper install: $400–$900. Free written quote always.
Will fixing the chimney definitely fix my smoke problem?
In about 90% of cases — yes. The remaining 10% are house-pressure issues (range hoods, dryers, HVAC competing with the fireplace) where the chimney is fine and the house is the problem. We tell you honestly which one it is, with data.
