11 Color Codes You May Need to Decipher the HVAC Thermostat Wiring Diagram

There are many people that feel confident about working around electricity I am not one of those people. There are many ways to go about this safety, but above all else this safety is necessary to keep you, your family, and your HVAC system safe. If you do not feel comfortable around electrical codes, wiring, and systems, please contact a qualified electrician. However, I have made this HVAC thermostat wiring diagram to help those of you that are capable and comfortable around electrical systems.


Before I start, I would like to state that you should always make sure that the unit has no electricity flowing through it when you start toying with wires. This HVAC thermostat wiring diagram example uses the codes most commonly used, but you will want to make sure you have a system with no electrical power going through it. You can do this by turning off the fuse or circuit to the HVAC unit. You will also find that some systems hold power, and you will need to release the excess electricity appropriately.


Color Terminal Name FunctionRed (R) Hot part of the transformerYellow (Y) Compressor activityWhite (W) HeatingGreen (G) Furnace blower fanOrange (O) Energize to heatBlue (B) Energize to coolBlue, Pink, Tan, or Gray (E) Emergency relay on heat pump optionalGray or Tan (T) Outdoor reset for anticipatorPink or Other Color (W2) Second stage of heat correlates with (W)Pink or Blue (Y2) Second stage compressorBrown, Blue, Gray, or Tan (L) Indicator service lamp


There are a few basic color codes you will find on any HVAC thermostat wiring diagram. Of course, some manufacturers have specific color codes, but you can easily find specific color codes by contacting the manufacturer directly or by doing a search via the internet. When you start working on a HVAC unit, knowing the proper color codes for each system will insure you are getting a good place to start when looking for problems in the system.


One example of difference that is important is the (B). York and Trane (B) is a lot different than the (B) for Ruud, Rheem, and Weatherking systems. Make sure you have specifics for you continue. Finding the appropriate color codes for your HVAC unit will get you a basic start to fixing your HVAC unit yourself.

About The Author:
Alphonso has been working in the home remodeling industry for last 5 years. Take advantage of his experience and written material on HVAC at his website at http://www.improve-home.com