If your home lacks a C-wire (common wire) and you want to install a Cielo Smart Thermostat, one option is to run a new wire from your HVAC control board to the thermostat. However, this can be time-consuming and challenging.
A more convenient alternative is to use a C-wire adapter. This device ensures a reliable power connection between your thermostat and HVAC system by providing a dedicated power source.
Cielo smart thermostats come with a C-wire adapter included in the box for easy installation if your home doesn’t have a dedicated C wire.
When to Use the C-Wire Adapter
Use the CWA when:
- Your current thermostat wiring does not have a C-wire.
- You want to avoid running a new wire through the wall.
How It Works
The CWA is installed at the HVAC system control board, not at the thermostat itself. It connects directly to the HVAC terminals to simulate a C-wire connection.
- The adapter connects to 3/4 wire terminals from the thermostat on one end.
- On the other end, it outputs five wires (R, C, G, Y, W), which are connected to the HVAC control board.
Important Information
- Cielo smart thermostats do not support connecting an accessory (humidifier or dehumidifier) and a C-wire adapter simultaneously.
- CWA does not work with dual transformer systems, fan coil, communicating units, & heat-only installations.
Compatibility
Note: If you're not sure about the wiring configuration, refer to the compatibility checker.
Common Wire Adapter (CWA) Wiring Configuration
Here’s how the terminals are typically labeled and used:
3-Wire Cooling Systems (R, Y/Y1, G) with Common Wire Adapter (CWA)
4-Wire System (R, Y, G, W) with Common Wire Adapter (CWA)
Installing the C-Wire Adapter with the Cielo Smart Thermostat
Step 1: Locate the existing wires at the control board
Identify where the three or four thermostat wires (typically R, G, Y, W) are connected on your control board.
Step 2: Disconnect the wires
Remove these wires from their current terminals on the control board.
Step 3: Connect the wires to the C-wire adapter
Insert the R, Y, G, W wires into their corresponding terminals on C-wire adapter.
Step 4: Connect adapter wires to the control board
Securely connect all the wires coming out of the C-Wire Adapter to the corresponding terminals on the control board of your HVAC system.
Step 5: Mount the C-Wire Adapter and Close the Panel
Place the CWA at a suitable location inside your HVAC system. Close the HVAC cover panel securely and return to your old thermostat.
Note: Make sure to close the panel as some systems may not turn on if the panel is not closed properly.
Step 6: Return to Cielo Smart Thermostat to connect the wires
Connect the wires as shown:
3 Wires
4 Wires
Then, connect the remaining wires to their corresponding terminals (press terminal block buttons for ease of insertion).