Product review (5 stars): My fiance has some electrical experience and replaced both parts fairly easily. It took him approximately 2 hours
I started getting the dreaded error message E64 on my Frigidare Affinity Dryer.  My dryer would still heat up but about half way through the cycle would quit.  You could restart it and it would go halfway through the cycle and quit again.  I googled the area and first found that it could be the heating coils but that didn't make much since as I didn't think it would heat up so effectively if that was the case.  I did more research and found that it could be the thermostat and the heat safety part Frigidaire 3204267 Safety Thermostat for Dryer.  My fiance has some electrical experience and replaced both parts fairly easily.  It took him approximately 2 hours.  He followed directions that were easily found.  I highly recommend going this route first if you have a little bit of fix it skills.  Costs a lot less than a service call.  The coils aren't difficult to get at if it turns out to be the problem.