The IceCap ATO Solenoid (SV-02) replaces the pump in the IceCap ATO as a way to provide the control of water flow from the Top Off System in situations where there is already a flow of water to the ATO Solenoid. This includes use with a RO System. When the water level drops below a set point the IceCap ATO will have the Solenoid open to allow the flow from the RO System.