Thanks for the welcome
My aquarium is in my bedroom and it usually gets pretty warm later in the day, though when it does, the heater shuts off to keep things at 78 degrees.
I have a theory

, the instructions said something like "DONT MOVE NOB MORE THAN 1 NOTCH PER HOUR", but it didnt say why. Well when I got it I turned it off, and I did move it rather fast about half way and it appeared to skip notches because when i moved it so fast, the nob turned very smoothly rather than normally moving in notches.
So my theory is that maby i've brought the nob out of allignment, so what Ill try doing is when I get home, Ill move the nob really fast about half way in the other direction, then Ill slowly bring the nob back down to low according to the instructions.
And Ill be keeping close watch of the temperature. Ill let you know what happens. Hopefully this wont bust my heater, but as of this point I dont really care much since I have so little room to adjust the temperature as it is anyway.