13 Gallon jacketed still using oil and 2k heating elements, 4" column with bubble plates and deph. cooling water 90 degrees. I've disassembled and cleaned the plates 3 times, swapped section gaskets, added heat, removed heat and it still does this. Oil temp stays rock solid but I swapped out controllers to be safe. This is a low wines spirit run on neutral and day one I pulled off 4 large masons of fores and early heads with no issue. Shut it down and started the spirit run the next day without ever taking it apart. It has done this all 4 times now and I cannot figure it out. Videos below.
https://vpn.winntech.net/crash/surging.mp4
https://vpn.winntech.net/crash/surging2.mp4