2 Wire Furnace Thermostat Wiring. Very simple two wire red and white heat only furnace to which I have several Nest Thermostats working fine. Once your c-wire is ready follow these steps to install your new thermostat.
A two-wire thermostat has two terminals labeled R and W. Label where the wires are connected on the thermostatCheck to see if they match the industry standard listed above. Furnace 2 wire thermostat install.
These letters stand for red and white so if those are the colors of the wires connect the red one to the R terminal and the white one to the W terminal.
Variety of 2 wire thermostat wiring diagram heat only. These letters stand for red and white so if those are the colors of the wires connect the red one to the R terminal and the white one to the W terminal. The guide covers four and five wire designs so the only thing holding you back is whether the original installation is compatible. If the wires are different colors check the connections on the appliance control panel.
