Dryer Vent Roof Cap Rattles After Chimney Work: Causes, Fixes, and When to Call a Pro

Run one medium load and track dry time, flap movement, exhaust strength outside, and room temperature. A simple baseline makes it easier to spot whether the issue is isolated or recurring.

Common causes include crushed transition ducts, loose clamps, clogged elbows, wall-cap hinge wear, and weather-driven pressure reversals. Small restrictions often stack together and create bigger performance drops.

Call a pro if symptoms return soon after cleaning, airflow is weak at the exterior outlet, the vent path is long or concealed, or you notice recurring heat and moisture in the laundry room.