An intermittent regulator is provided in which the regulator alternates between supplying partial vacuum to a patient for withdrawing fluids from the body of a patient, and supplying atmosphere to a patient, at a selected intermittent rate, that is adjustable upon adjusting a timing mechanism. The timing mechanism is isolated from communicating with the vacuum being drawn from a patient, separating the regulator into a “wet” side and a “dry” side. The regulator includes a piston and spool, each having magnets therein, whereby intermittent motion of the piston controls the motion of the spool and which thereby controls the opening of ports for delivery/non-delivery of vacuum to a patient. An alternative embodiment has porting for sensing occlusion in the patient line and converting the regulator from a continuous-on operation to an intermittent operation. An alternative embodiment has separate air inlet and outlet conduits to atmosphere from the “dry” side of the regulator.