Honeywell Thermostat Wiring Diagram. Here we focus on the 4 wire t stats. Other thermostats have fewer wires.
If it's a new installation, you may have to identify the wires first. Again referring to the honeywell thermostat ct31a1003 wiring diagram, you can see it requires only two wires, r and w. It doesn't control cooling and, because it's a mechanical thermostat, it doesn't need power for internal functions, so it has no c wire.
A wiring diagram is a streamlined standard photographic depiction of an electrical circuit.
Highperformancehvac.com read electrical wiring diagrams from negative to positive in addition to redraw the circuit being a straight collection. It shows the parts of the circuit as simplified shapes, and also the power as well as signal connections between the devices. Again referring to the honeywell thermostat ct31a1003 wiring diagram, you can see it requires only two wires, r and w. It is a diagram drawn to i.e.e.