Since I setup my tank a few days ago, my Eheim Jager 100w heater light has not turned off. It's been at least three days in the sump. Obviously I'm not looking at it 24/7, so I can't tell if its just coincidence that when I look at the light is on and other times it's off. I checked the tank temp and it's dead-on at 79 which is how the heater was set before I plugged it in. I didn't calibrate it. Should I be concerned?