splitsecond

hello all my first post here i just got a tub gave to me and the tub was purchased new by my inlaws it was used with no problems and it got a small leak so it was shut off they had a person come repair the leak and he looked at the controll box (sentry 800) he told them a wire was not hooked up they think it was to the heater thats when problems started he told them only 110v was hooked up to the heater . that is were my question is .i see were it looks like a wire was pluged in to the 3 little heater plugins. there is nothing pluged in to the middle one.looking at some of the pics of other sundance models i see jumper wires going from the first to the second and the third i will post a pic of the control unit if any one has info or has a pic of this unit it would help a ton thanks for all of your time