A control system having a pressure regulator, first pilot, and second pilot. The pressure regulator has a fluid inlet, fluid outlet, and actuator assembly with a cavity divided into a first chamber in fluid communication with the fluid outlet and a second chamber. The first pilot has a first setpoint and the second pilot has a second setpoint, less than the first setpoint. The first and second pilots fluidly couple the second chamber to the fluid outlet and isolate the second chamber from the fluid inlet in a first mode of operation, isolate the second chamber from the fluid outlet and fluid inlet in a second mode of operation, and fluidly couple the second chamber to the fluid inlet in a third mode of operation.