Presented are embodiments of pressure relief valves for use in water supply systems to prevent damage thereto caused by over pressure resulting from freezing of the water therein. In one embodiment the pressure relief valve is included in an electromechanical solenoid controlled water valve particularly useful in appliances such as washing machines, water heaters, refrigerators, etc. Prior to the main valving member, a spring loaded pressure relief valving member is included. Once the pressure within the valve exceeds the spring force, which is set below the failure pressure of the water supply system and the valve, the pressure relief valving member opens to allow a flow of water therethrough. Alternatively or additionally, a temperature active device such as a bi-metal disc is interposed between the spring and the pressure relief valving member to provide actuation thereof below a predetermined temperature.