Taco Zone Sentry Zone Valves provide on-off, normally open or normally closed control in both open and closed hot or chilled water systems. The valves can be used in a wide variety of heating and cooling applications, primarily designed for use with fan coils, radiators, convectors, air handlers, heat pumps and radiant applications. The Zone Sentry is the most technologically advanced zone valve ever made. It's also simple to install and operate. The valve can be installed in any direction, in any orientation. Taco then went a step further, allowing the operator to be mounted to the valve body in either direction (see Figure A of the manual in the "Manuals" tab), great for those tight baseboard jobs. Snap-in quick connects on the back of the valve make for a simple, secure and fast wiring hook-up. A green LED light shows full functionality of the valve's operation and thermostat status. Under a no power situation the manual override button located on the top of the valve allows the ball to be rotated up to 90° and is also marked with a slot to indicate the position of the valve.