Part 4/8:

The Mechanics Behind the Thermostat's Commands

To see how a thermostat communicates with a heating system, let’s consider a typical furnace setup. At the furnace's control board, the various wires connect to specific terminals: the red wire supplying power, the white wire triggering heating, the yellow for cooling, and the green for the fan. When a thermostat connects the red wire to the white wire, it signals the furnace to turn on. The system will continue heating until the thermostat no longer detects a voltage on the white wire.