Smart Thermostats almost always require them. The internet of things is on the rise and one of the easiest and most useful applications of this is the smart thermostat. Popular smart thermostats that come to mind at the Nest, Ecobee, and the Honeywell Lyric most of these and other smart thermostats that come with WiFi. Installing these thermostats can be tricky due to the C-Wire or Common Wire. For thermostat installations you need to have a set of wires that run from your heating and/or cooling system to your thermostat(s). In instances where you just have a boiler or furnace without the ability to cool you see a thermostat with just two wires, red and white. If you have a cooling system with your heating system you'll most commonly find the thermostats using 4 wires. If you add a smart thermostat you're going to need a fifth wire, the c-wire. C-wires help delivery more power to the thermostat to power the Wi-Fi functions. Adding this wire can be difficult as it requ...