Nest thermostats are designed to work without a C wire in most homes. But some systems may require a C wire for consistent power. The Nest Power Connector is a simple and affordable alternative to a C wire, and costs much less than hiring an electrician to install a new C wire through your walls. The Nest Power Connector doesn’t require any new wiring or drilling. It attaches to your furnace, air handler, or zone controller and comes with simple instructions for easy installation.