What does the Check Vent indicator light mean?

The CHECK VENT indicator signals a serious blockage or restriction in your home's exhaust ductwork that is reducing airflow from the dryer. This light does not indicate a problem with the dryer itself and is not covered by the dryer warranty. If it blinks, check for a crushed duct, ductwork that is too long, lint buildup, or a damaged outside vent hood, and contact a duct cleaning service. (Page 23, 29)