My ATL-1000 process BW at 24C with a water bath, so I would guess that not all ATL-1000's are programmed in the same way. I don't now how to solve your problem, but I suggest that you contact Klaus-D. Seynsche at: http://www.fotolaborservice.de/. He has supplied parts to my Jobo in the past, and probably know what there is to know about these machines.

Trond