Hvac Thermostat Wire Colors. It is a red wire and comes from the transformer usually located in the air handler for split systems but you may find the transformer in the condensing unit. The most common is 18 5 5 strand 18 gauge.
Rc red wire power 24 vac rh or 4 red wire jumpered power 24 vac w white wire for heating enable y yellow wire for cooling enable. A heat pump system on the other hand has eight or more different thermostat wires. Orange this wire connects to your heat pump if you have one.
Rc red wire power 24 vac rh or 4 red wire jumpered power 24 vac w white wire for heating enable y yellow wire for cooling enable.
Yellow the yellow wire connects to your compressor. Types of thermostat wire. C wires or varying colors apply to every thermostat but blue c wires belong to thermostats attached to a heat pump. The main difference setting each apart is the number of colored wires.
