Matt was on time and immediately told me where the problems were and what to watch for the next time. He also gave me helpful advice on what to put on the outside vent to keep critters out. Although I used to think cleaning the screen every time was enough, Matt showed me what can happen when you don't take care of the main vent. Yikes. Friendly, courteous, professional- all the other positive reviews are spot on! Thanks Matt- I've already given you name to a few friends!