jager heater issues?

[robzilla]

hi, i'm having troubles with my jager heater. ive got three of them and yet regardless of the setting on the heater, the tank stays at 82 degrees. ive tried all three seperately and even if you have it set at 75 degrees the heaters come on and off to maintain the temp.
am i missing something with the little blue pull up tab on the heater or ????
this should be something simple.....as on my other tank, i have a different brand and no issues