HEATER FAILED AGIAN! Any brand/style recommendations?

[Clown]

Well this is the second heater that has now failed on me cooking my tank,
I had woke up this morning noticing that my BTA had moved being in a rush to get to work i didn't check anything on the tank
once i got home i checked it out and the nem wasn't looking so good (as if its insides were coming out its mouth) So after cooling down the tank (+35)
I had read a little bit on it and had learned that it can still be saved so i poped it in the 75 gal and its looking much better now
i placed it ontop of the rock and it moved under a rock its fully open but hiding under a ledge not really any light or flow there any ideas?
ANYWAYS
so this is my second heater failing taking out some of my live stock any suggestions on a style/brand that was worked well for you?