How to Wire a Zone Valve

A zone valve helps control the heat from a thermostat for an area of your home, such as a bedroom or living room. A control box is wired to thermostats in your house and controls the zone valves. When a zone valve receives an electrical signal from its thermostat, it will open or close. Heated water from a boiler can pass through an open zone valve to heat the thermostat's area. Try these steps to wire a zone valve.


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    Familiarize yourself with the instruction manual for your zoning system. Your boiler's owner's manual may also have instructions for zone valve wiring. Look for any diagrams to help you connect valve wiring in the system's control box.
    • If you do not have your particular zoning system's instruction manual, try looking for it online through the manufacturer's website.
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    Turn off all electricity to your boiler. Depending on your system, this may involve flipping an electrical switch or shutting off circuit breakers located ahead and at the boiler.
  3. Image titled Wire a Zone Valve Step 3
    Take off the cover from your zoning system's control box. This box or panel should be located on a wall near your boiler.
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    Examine the interior of the control box. It may have terminals marked "T" in it that go to the boiler to control when to send the boiler's heated water. The control box should also have a transformer of a certain voltage, perhaps 24 volts, to carry power between the thermostat and zone valves.
    • Zone valve manufacturers often label the connection terminals in their control boxes to make it easier to wire their systems. Use these labels to help you make the appropriate wiring connections.
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    Wire 1 terminal of your system's transformer to the appropriate thermostat. Connect the other side of the thermostat to the first terminal of the zone valve operator.
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    Connect the second terminal from the zone valve operator to the remaining terminal in the transformer.
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    Connect a wire from the zone valve operator's second terminal to 1 of the boiler's "T" terminals.
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    Wire the third terminal of the zone valve to the other "T" terminal. This configuration should wire 3 zone valves.
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    Wire any additional zone valves as instructed by the manufacturer. The number of zone valves that a control box can handle depends on the model. It may range from 2 or 3 zones to 6.
    • To wire additional zones, 1 or more extra transformers may be required as well.
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    Connect the transformer(s) according to your instruction manual. Try matching up wires from labeled terminals in the control box to matching terminals for the transformer(s).
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    Turn the electricity back on for the boiler.


  • Benefits of using zone valves to control the temperature in a house include lowering energy usage and utility costs.
  • System zoning can refer to the type of heating and cooling system that uses zone valves and thermostats to separate a house into different zones to regulate their temperature.
  • Zone valves may also be called dampers.

Things You'll Need

  • Instruction manual for system zoning
  • Boiler
  • Switch or breakers for boiler's electricity
  • Zone control box
  • Transformer
  • Wiring for control box

Article Info

Categories: Cabling and Wiring Connection