tractorclub

I have an old and normally very reliable Balboa Hot tub it has a BF75 controller. It appears to have several filtration modes ( F0, F2, F4, F6, F8, FC) I have it set to F0. I also found another setting C1 and C2 it is currently set to C1 and I have no idea what this means. I get a code on occasion the says Sb. I THINK that means sensor 2 fault. But I cannot find a manual for this. It seems to run fine otherwise. It controls the temp to 102F and the heater turns on and off accordingly. I just wont stop pumping. Regardless of what I do. If I retest the breaker, the pump stays off for about a min then starts again. Please help!