Some of the homes in the Walden neighborhood, in Silver Spring Township, were not built to code. “I would think it is everybody prior to 2013 with a second-floor laundry,” said Sam Boyd, a homeowner.

You risk a serious dryer fire when lint, poor materials, or a blocked, long run restricts airflow. Replace plastic or foil hoses, keep the duct short and straight, and clean the entire vent at least ...