Update: figured out why my callback rate on dryer repairs dropped after 22 years in the trade
For the first two decades of fixing dryers I blamed the machines when customers called back, but last Tuesday a guy in Council Bluffs handed me back a lint screen I had cleaned and told me the real issue was something I had never once checked. He pulled out a $14 vent brush from his truck and ran it up the exhaust duct, and a wad of lint the size of a soccer ball came out. I had been replacing thermal fuses and heating elements for years without ever asking when the duct was last cleared. That afternoon I started adding a duct check to every dryer call, and in three weeks my callbacks on those jobs dropped from about one in five to zero. Turns out the fix was never inside the box, it was the pipe going out the wall. Anybody else out there charge extra for a duct cleaning or just fold it into the service call?
A wad of lint the size of a soccer ball? I have pulled some nasty stuff out of ducts but that is wild. Twenty two years and nobody ever told you to check the pipe, that is crazy.