iDevices Thermostat - Wi-Fi Thermostat Works with Alexa Works with Alexa for voice control (Alexa device sold separately). HVAC Compatibility: Heating: 1 and 2 Stages (W1, W2),Cooling: 1 and 2 Stages (Y1, Y2),Heat Pump: 1 and 2 stage with Aux or Emergency Heat (O/B, Aux/E).Fan Control: G,Power: C (required), RH, RC,Converts to Fahrenheit or Celsius Customize the temperature of your home from anywhere with the iDevices Thermostat. Use Siri or Alexa voice commands and custom scenes (i.e. "Bedtime") to make your home cozy when you're there. Quickly adjust temperatures no matter where you are with the iDevices Connected app on your iPhone, iPad, iPod touch No Hub or Subscriptions - With the iDevices Thermostat, your home's Wi-Fi and an iPhone device is all you need Voice Control - The iDevices Thermostat responds to Siri, Alexa, or the Google Assistant voice commands, letting you control your home without even picking up your phone Access Anywhere - Control and monitor the iDevices Thermostat from wherever you are using your iPhone or Android device. No Apple TV needed Works with most heating and cooling systems - Requires a 24VAC "Common" wire, also referred to as a "C-Wire." For any questions or concerns about compatibility, please contact our customer support team