Abstract: A suction-actuated control system (10) for a whirlpool bath/spa installation includes a suction-side transducer (52) connected in the suction inlet path and a controller (54). The suction-side transducer (52) transmits an air pulse to the controller (54) when pressure in the suction path drops below a pre-determined value caused, for example, by a full or partial blockage of a suction cover (26) by a wash cloth or an article of clothing. The controller (54) includes an electric switch (62) in circuit with the recirculation pump (34) and a bi-state controller (66) that actuates the electric switch (62) between its ON state and its OFF state. An abnormally low pressure in the suction path to the recirculation pump (34) caused by a full or partial blockage of the suction cover (26) will cause the controller (54) to shut-off the recirculation pump (34). After the obstruction is removed and a short time delay, the user can actuate a user ON/OFF control (56) to restart the pump (34).

Abstract: A flow-regulating valve is located in the outlet of the housing of a centrifugal pump instead of in downstream piping, to regulate the flow from the pump without the usual acoustic disturbance caused by flow. The arrangement is especially adapted for hydro-therapeutic installations, such as a spa, hot tub, whirlpool bath or the like. The valve is operated by a control conveniently accessible to the occupant of the hydro-therapeutic installation. The control can be in the form of a knob connected to the valve by flexible cable or the like or in the form of a single push-button which controls both the electric motor for the pump and an electric motor which operates the valve.