There are quite a few thing you can check to see if your dryer vent needs cleaning. Let’s start with the most important signs you must check first.
Drying time. Lack of the air flow from the dryer machine will result in increasing of drying time. The normal drying time is between 40 and 60 minutes, of course, depends on your load. If you notice that it start taking more the an hour or the clothes are still wet after 1 drying cycle – then it’s time to get your dryer vent cleaned.
Outside cover. Every once in a while you should check your outside dryer vent cover. Visually inspect it and see if the outside exhaust vent opens at lest 45 degrees while the dryer is on. You can also check if there is a bird nest inside of the line.
Back of the dryer. If the dryer vent needs cleaning and has not enough air flow the back of the dryer machine will get unusually hot. As the result, burnt smell is evident in the laundry room.
Smell. Clogged dryer vent can result in collecting water in the line or/and the dryer machine. You can notice a Moldy or Mildewy smell in the laundry room.