Laundry dryer's thermal fuse keeps blowing off every few months. What could be the cause?
Replace the thermostat also, it should be right there next to the fuse.  Its probably reading a little low, or intermittently failing, so the dryer is getting slightly hotter than is supported and the thermal fuse blows.  Also, while you have the cover open, you can be sure to vacuum the vent and everything making sure there are not restrictions like others have mentioned.  For me, the thermostat solved it after I went through about 5 thermal fuses.