My understanding is that the heaters used in the older ST and STL series cameras aren't available at SBIG any more. Has anyone found a replacement heater that can be used? I have already spoken with Bill about this as well. I have three heaters installed on my STL-11000 and they may not be functioning properly as the CCD chamber window seems to be dewing at times, usually the wee hours of the morning resulting in the last two hours or so of data being useless. My understanding is the heaters are powered off the 12 volt fan circuit and come on when the camera is powered.