Here I am a professional in the trade of cleaning dryer vents.  And to my embarrassment, I recently had a situation come up.  My wife complained of smelling smoke when she dried some clothes.  I poopooed her.  First, that is never a good idea.  But here is where my “knowledge” got in the way of actually looking at her complaint.  I “knew” my dryer vent exited my dryer thru a 18″ flex hose and went directly outside thru a 5″ wall, so it could not be a problem.  In my mind, there was no way the vent could be plugged and capable of causing a fire.  When I finally got around to looking at it, I found that the maid had pushed the dryer vent back, too far against the wall, and crimped the flexible vent nearly closed.  This did not allow full exhaust flow, lint built up, and the heat sensor did not shut off the dryer.  Low and behold, the trapped lint actually started to smoulder.  It was quite by luck, that I did not have a full on fire.  The inside of the dryer actually turned black!! So, I learned two very important lessons.  One, never poopoo the wife, and secondly, even very short dryer vent lines can cause a problem.  I found out first hand that dryer vent fires are a real threat. One of the most common indications that the dryer vent is starting to plug is the length of time it takes for clothes to dry.  Most dryers have a sensor in them that will shut off the heat as a safety precaution.  When the dryer vent gets plugged the heat or pressue (depending on type of dryer sensor) will build up and automatically shut off the drying function.   The dryer will continue to tumble and turn but lacking heat, the clothes will take forever to dry.  So, increased drying time, is often a signal.  I, regularly, get calls that people will have just bought a new dryer, and the new dryer doesn’t work.  the problem was not the old dryer, but a plugged vent line. Just last week, we got a call from a customer.  Their dryer vent was supposedly plugged.  Well, it was! The dryer vent was under the slab of the house.  It exited the dryer, went down traveled...