I read the posts concerning what to do when this dryer heats up then stops heating. I replaced the coils as recommended and the burner ignites as usual then after heating for a few seconds the flame goes out. Same thing it was doing before. So i thought about it and wonder if it couldn't be the hi-limit thermostat?? In troubleshooting guides it says it could be the radiant sensor opening prematurely. but seeing as it burns for a little while..goes out then comes back on after a period..???