I have just purchased this grill and have used it twice. Like it very much, but on the second use, the small light that lights when you turn it on and then goes out when it reaches proper temperature did not light at all. The grill was hot and I was able to cook on it, but the light did not light when I turned it on, so I could not tell when it reached temperature. What is the problem? Also, the heat control is difficult to insert into the unit.