I rented a house once that the previous tenant had been living in for about a year with 3 little kids. She had mentioned to me that the dryer worked ok when she moved in but it wasn't working anymore. It still ran but it didn't really dry anything.

Not a big deal I thought. Went over to the dryer and took a look at it. First thing I did was pull the filter. It was clogged solid. She didn't even know it had a lint trap, never mind that you're supposed to clean it after every single load. Not only was the trap plugged, so was a bunch of the hose and ductwork. I spent several hours taking everything apart and cleaning it out, finally got it all back together, turned the dryer on, and it worked like a champ. Not a single problem for the 7 yrs I lived there.

She was a lady already in her thirties with 5 kids (3 lived with her)... you'd think she would have known how to use a dryer at that point. I'm just happy she never burnt the house down..