A liquid level control module comprising an elongated tubular housing immersible through a surface of a liquid and into a bulk volume of the liquid, and first, second, and third electrical switches, and first and second floats movable along the tubular housing. The first electrical switch is disposed within a lower portion of the tubular housing, the second electrical switch is disposed within an intermediate portion of the tubular housing, and the third electrical switch is disposed within an upper portion of the tubular housing. Each of the switches has an open state and a closed state. Motion of the first float relative to the first switch changes its state. Motion of the second float relative to the second switch changes its state, and motion of the second float relative to the third switch changes its state. Thus a two-float module may provide three level control signals.

A liquid level control module comprising an elongated tubular housing immersible through a surface of a liquid and into a bulk volume of the liquid, and first, second, and third electrical switches, and first and second floats movable along the tubular housing. The first electrical switch is disposed within a lower portion of the tubular housing, the second electrical switch is disposed within an intermediate portion of the tubular housing, and the third electrical switch is disposed within an upper portion of the tubular housing. Each of the switches has an open state and a closed state. Motion of the first float relative to the first switch changes its state. Motion of the second float relative to the second switch changes its state, and motion of the second float relative to the third switch changes its state. Thus a two-float module may provide three level control signals.

A shelf is arranged to pivot about a pivot zone. The shelf has a center of gravity offset from the pivot zone. The shelf has a first angular range about the pivot zone configured to situate a linkage in a valve activation position. The shelf has a second angular range about the pivot zone mechanically configured to situate the linkage in a valve de-activation position. An interaction portion is mechanically configured to urge the shelf from the first angular range to the second angular range by a float moving in a first direction.