I have an 08 451 for two. The automatic temperature control stopped working years ago, as I understand most of thelm did. Since then, I have had only hot or cold, which I could live with by varying the fan speed. Recently I have an additional problem....with the heat control in the fully "up" position, I get max heat, but at odd intervals it starts blowing cold (or semi-cold) air. By moving the lever down and back up to maximum quickly, hot air resumes. ( I assume the problem is associated with an air diversion vane.) Has anyone else had this problem, and found a solution? Don't want to get too involved without a little more information as to what's involved. On the same subject....has anyone succesfully restored one of these 08 or 09 controls to their original automatic temperature regulatiflunction? They really worked great when they were new!