Abstract: This is a digital solid state control system for pumping liquid to regulate the condition of the liquid in a container, such as the liquid level. One pump is turned on when the liquid rises to one level, and another pump is turned on when the liquid rises to a higher level. An alarm is activated if the liquid rises to a still higher level or if a leak occurs in either pump. The control system alternates which pump turns on first in successive operating cycles. If a power failure occurs while both pumps are on, when power is restored only one pump comes on immediately; the other comes on only after a time delay.