It is better to take a good up close photo of the old thermostat and what terminals the colored wiring are terminated. O orange wire to the o terminal for the reversing valve altough a few manufacturers use the b terminal for the reversing.
Thermostat Wiring Diagrams Wire Installation Simple Guide
Hvac wiring diagram colors. Types of thermostat wire. I explain what each of the letter terminals are for the voltage path how it works and also the normal color code used. C blue wire to the c terminal sometimes you will this. R red wire to the r terminal g green wire to the g terminal y yellow wire to the y terminal w white wire to the w term. I discuss how to wire the contactor and what the difference is between the. The most common is 185 5 strand 18 gauge.
Finally this way you can match up the appropriate wire color coming from the thermostat to what it controls in the equipment. There are a variety of thermostat wire types. What the color code means for air conditioner and furnace thermostat wires. The main difference setting each apart is the number of colored wires. Hvac systems with more functions need more wires to communicate to and from the thermostat. The 5 strands of wire provide enough functions for the modern.
In either case it is crucial to find the wiring diagram for the unit. This video is part of the heating and cooling series of training videos made to accompany my websites. Basic thermostat wiring colors air conditioner systems always remember when changing a thermostat for a new thermostat to take a photo of the colors and where they go on the old thermostat or get a pencil and paper and write it down. The red wire should always come from the hot side of the 24 volt transformer.
Gallery of Hvac Wiring Diagram Colors
