The Cielo Smart Thermostat allows you to connect a humidifier using its dedicated CWA terminal. The wiring setup will vary based on whether you're installing a 1-wire or 2-wire humidifier.
Cielo Smart Thermostat supports one 1-wire or 2-wire accessory (humidifier/dehumidifier) through the CWA terminal, but does not support an accessory and Common Wire Adapter (CWA) at the same time.
Firmware Requirements
Ensure your device is running the latest firmware version (1.3.0, 1.2.4, or higher).
To check the firmware version - Go to Menu > Scroll down to About Device > Firmware Version.
Types of Humidifiers
Steam Humidifier
A steam humidifier is a whole-house humidifier that operates by boiling water to produce steam, which is distributed through the ductwork.
💡 Tip: Steam humidifiers typically include a steam canister. If yours has one, it's likely a steam humidifier.
Evaporative Humidifier
Evaporative humidifiers use a fan to draw air through a wet filter, allowing water to evaporate and add moisture to the air.
1-Wire Accessory
Accessories with a 1-wire attach to the thermostat's CWA terminal and use the HVAC system's 24V power for activation, sourced from the Rc terminal.
The connection of the 1-wire system is depicted in the following diagram:
2-Wire Accessory
Accessories with 2-wires have their own power source and are electrically isolated from the HVAC equipment. The thermostat's CWA terminal would be used to connect with the wire coming from an additional isolation relay (separately sold and attached).
The connection of the 2-wire system is depicted in the following diagram:
Before You Begin
- Identify the humidifier control wire. Look for labels such as H, HUM, or HUM1.
- If you don’t have a common wire (C-wire) and are using a C-wire adapter to power your Cielo Smart Thermostat, your accessory cannot be connected because it must be wired to the CWA terminal.
- If you have a 2-wire humidifier, a 24V AC isolation relay is required to install. For assistance, please contact Cielo Tech support at:
📞 Call: +1 (425) 529-5775 (9 am - 9 pm ET | Mon - Fri)
📧 Email: sale@cmerweb.com
⚠️ WARNING
In case of dual power source, i.e., Rc & Rh, power the accessory (humidifier) using the cooling system’s power source, i.e., Rc and C. DO NOT use the heating system’s power source, i.e., Rh & C, as it may damage the equipment.
WIRING INSTRUCTIONS (Humidifier)
Step 1: Power OFF the HVAC System
Power off your HVAC system using the:
1. The master switch OR 2. The circuit breaker
To be on the safe side, ensure that the system is completely switched off. Double-check that:
- No air is coming out of the air vents.
- The main flame is extinguished in case of a boiler.
Step 2: Remove the Thermostat
Detach the Cielo Smart Thermostat from its backplate.
Step 3: Locate the Accessory Wire
Locate your accessory wire labeled as H, HUM, or HUM1. This wire controls your humidification system. Ensure that the accessory wire is coming directly from the system to the thermostat.
Step 4: Connect to the CWA Terminal
Connect the humidifier wire to the CWA terminal (press terminal block buttons for ease of insertion).
Step 5: Reattach the Thermostat
Align the Cielo Smart Thermostat with the backplate and press gently to fix it properly.
Step 6: Restore Power
Go to your HVAC system and turn ON the power from the master switch or circuit breaker.
Configuring Humidifier on Cielo Smart Thermostat
Step 1: Access Settings
Go to 'Menu' and select 'HVAC Settings.'
Step 2: Reconfigure Equipment
- Select 'Reconfigure your equipment'.
- Tap 'Start'.
- Cielo Smart Thermostat will automatically detect the connected wires. Tap ‘Next’.
Step 3: Confirm Configuration
You’ll be asked, “Do you have any accessory connected to the thermostat, such as a Humidifier or Dehumidifier?”. Tap ‘Yes’.
Carefully go through the caution note. Tap ‘Next’.
Step 4: Choose Heating Source
Configure your heating source as you did in the initial setup. Then proceed forward.
Note: This screen may vary depending on your configured equipment.
Step 5: Select Accessory Type
Select your accessory type:
Then select the appropriate options:
1. Does your humidifier run independently of your heating equipment?
Some humidifiers are designed to work in conjunction with your heating equipment, while others can operate independently. Refer to your system’s manual to identify the type of humidifier you have.
📢 Note: If you have an evaporative humidifier, it operates in conjunction with your heating equipment. In contrast, steam humidifiers can run independently of a heating system. If you're not sure which type of humidifier you have, one way to tell is that steam humidifiers use a steam canister to produce moisture.
2. Does your humidifier need an equipment fan?
- If your humidifier operates independently of the heating equipment and uses its own fan to circulate air, select ‘Yes’.
- If your humidifier’s operation is dependent on the heating equipment, select ‘No’.
Tap ‘Next’ to continue.
Step 6: Final Step
Choose how the temperature should be displayed.
Toggle ON the humidifier & set your preferred humidity level. Tap ‘Next’
Setup Complete
Your humidifier is now successfully connected and configured with the Cielo Smart Thermostat. If you encounter any issues or need further assistance, feel free to reach out to Cielo Tech support at:
📞 Call: +1 (425) 529-5775 (9 am - 9 pm ET | Mon - Fri)
📧 Email: sale@cmerweb.com