Professional electricians usually deal with smart thermostat installation since it will be connected to old wiring in the walls. When you call ACTexas, EPA-certified HVAC technicians visit your home to install your new thermostat. They'll access your breaker panel, turn off the furnace, and remove the existing device. They can also safely dispose of your old model. While there, they can help you set up the app on your smartphone. While it's possible to install a smart thermostat yourself, it's recommended to have a professional HVAC technician handle the installation. This ensures that the thermostat wires are correctly connected, and that optional trim plates, wall anchors, and other components are properly installed. A professional will also check for a C wire (common wire), which is often necessary for smart thermostats to function correctly.