The answer to 'why is my dryer vent odor' is that a clogged or dirty dryer vent is the most common cause of dryer vent odor. Over time, lint, dust, and debris can build up in the vent, preventing proper airflow and creating a breeding ground for mold, mildew, and bacteria that produce unpleasant smells.
Other potential causes include a damaged or disconnected vent, a vent that's too long or has too many bends, or a vent that's not properly vented to the outside. Dryer vent odor can also be a sign of a more serious issue like a gas leak or electrical problem.