Ruined? No, I am not concerned about that. But after spending way too much on this fermenter, I want the control afforded by this set-up. With the tighter thermowell that originally came with this fermenter I could hold an accurate +/- 0.5 degree. I would think with the slop in the new well that it would be much higher. In my very cold garage, there is a noticeable difference between 60 degrees and my normal wy1968 temp of 62 degrees.