My Kenmore gas dryer, model # 71802, won't stay hot. When the cycle first starts there is a flame. But after a short period of time the flame goes out and will not relight. I see a glow and then hear a click and the glow goes out, no flame. It was recommended I check the coils for continuity, which I did. They seem fine. I am learning as I go, and am beginning to wonder if I am over my head. Thanks for any advice!