The leading cause of clothes dryer fires is failure to properly clean and maintain them. Repairmen are being honest when they urge consumers to regularly maintain their appliances and remove the lint from the trap after each load.
What you may not know is that not just fuzz blocks airflow. Dryer filters can also build up an invisible film of dryer sheet and softener residue. This residue can block airflow through the filter just as much as lint can. To see if your filter has residue built up on it, hold it under a running faucet. If water beads up on the screen it has a dangerous build up of residue.
To rectify the problem, simply use soap and warm water and scrub the filter with an old toothbrush. It is recommended that you do this twice a year to avoid this being a problem.
It is also recommended that you not operate the dryer without the lint filter in place. On a yearly basis clean the lint from around the drum and from inside the vent pipe. Speaking of vent pipe, always use rigid or flexible metal venting material to sustain proper airflow and drying time. Throw away those old plastic flexible ducts.
Remember to make sure the air exhaust vent pipe is not restircted and the outdoor vent flap opens when the dryer is operating. This includes making sure that the flap is not blocked by snow during the winter months.
Properly maintain your dryer. Make sure the right plug and outlet are used and that the machine is connected properly, as well as grounded properly. Gas dryers should be inspected by a professional regularly to ensure that the gas line and connection are intact and free of leaks.
Avoid overloading the dryer and never leave a dryer running when you leave home or go to bed. Never dry items that have come in contact with flammable substances such as cooking oil, gasoline, paint thinner, or alcohol. Lastly, keep the dryer area clear of things that can burn, such as boxes or clothing.