Abstract: In a freeze protection-valve, a wax actuator is situated in a heat-conductive housing to which heat is conducted from the liquid system being protected. The housing prevents the actuator from triggering the valve to its opened condition while the liquid system is hot, but permits a rapid response when the liquid system is cool. In a snap-action freeze protection valve, the actuator is carried by the valve stem, and heat is conducted from the valve body to the valve stem through a sleeve through which the valve stem slides. The actuator moves a cam within the valve stem which operates a ball-type latch. The latch holds the valve in the closed position until the actuator releases the latch. Also disclosed is a remote-controlled valve operating mechanism which uses an electrically heated wax actuator to effect valve closure.