I just started working as a bartender where I now have to make hamburgers on a flat grill top. I was doing just fine but all of a sudden I noticed that burgers are not going as fast. I keep telling the boss that the grill is not getting hot enough but, he won't listen to me. I turn it on as high as it will go...450 and it is on all day. But still seams like it is boiling the burger in the grease instead of frying it. How can I personally test the grill to see what temp it is showing. I don't want to buy a tester, just to prove my boss wrong...What can I do?