I have a 2nd story gas dryer with venting that runs into the attic, into a booster fan and then out the roof. The booster has a warning light when something is malfunctioning. The light turned red. I called BenzVac and they made a quick convenient appointment with a 2 hour time-frame. The technician was friendly and very competent and quickly cleaned the vent by hand behind the dryer (access door) and then on both sides of the booster. he found the blockage at the roof line and pulled all that out by hand and then used compressed air to clean the whole thing. Great service, reasonably priced. I recommend. read more