I'm having issues with my dryer staying hot. It starts off fine then about 10 minutes later, the gas shuts off and the dryer gets cool. Then the glow plug starts up again, but the gas wont come back on. It keeps doing that and if I unplug it and wait about half an hour, I restart it again, it gets hot again, and shuts off again, repeating the cycle. I checked the flame sensor with omz meter and its saying the sensor is find. What could be the problem? Thank you.