What Is a Taco Zone Valve and How Do You Wire It?

The taco zone valve controls the flow of water in a hydronic heating/cooling system. The valve sends heated or cooled water to different parts of a building at different times of day by creating and controlling temperature zones. For safety and proper functioning, wire zone valves according to manufacturer's instructions.

Installing the zone valves involves assembling and attaching them to lines running from the boiler. The valves can be sweat into the line by cleaning the surfaces with a high grade flux and soldering with a 50-50 or 60-40 solder only. The control box is installed beside the boiler, and wires are matched and connected between the zone valves and thermostats in each room or zone. Cut off all electricity to the boiler during installation, drain it and turn off its water supply. It is essential that no power reaches the boiler during installation.

Using taco zone valve controls, or ZVCs, is recommended to simplify the wiring process when used with 2-, 3- or 4-wire zone valves. The taco zone valve controls are compatible with universal thermostats. The simple layout of the controls reduces the chance of incorrect wiring, and external indicator lights come on immediately as problems arise, reducing troubleshooting time.