gas dryer heats for only a few minutes

made by fridgedaier. just replaced the felt this weekend, so i know how to open it up. lint is all cleaned out of the ductwork.
heats up for awhile then quits heating. Figure it needs a coil kit or thermostat. how do i tell which part it needs? which is the most likely to fail?
I know this is not crummy dryer, but i’d rather not by another one.

I’ll bet dollars to donuts it is the coils on the gas valve. Tom http://www.applianceeducator.com

kayakcrzy–
you were right–it was the coils on the gas valve.
THANKS!
Ben