Google Nest Power Connector - Nest Thermostat C Wire Adapter - C Wire Adapter for Smart Thermostat - Nest Thermostat AccessoriesNest thermostats are designed to work without a C wire in most homes. But some systems may require a C wire for consistent power to your Nest thermostat. The Nest Power Connector is an affordable C wire substitute for homes that don't have one. It doesn't require any new thermostat wiring. And with simple instructions you can even install it yourself. If something is wrong with your Nest Thermostat, Google will alert you on device, through mobile app