Demystifying Thermostat Wiring Colors What Goes Where?

One of the most crucial items in your home is the demystifying Thermostats. The ability to manage the temperature makes your home comfortable, even on the hottest summer days and the coldest winters. You know how difficult it may be to set up a demystifying Thermostat if you’ve ever had to do so.

Because there is no regulation, you’re at the producer’s discretion when it comes to how they colour scheme their termination wiring. If you’re trying to replace one demystifying Thermostat with another, you’re in for double the headache since you’ll have to cope with the colour scheme methods of two distinct businesses.

However, color codes for different manufacturers may differ. You’ll know the color codes for the most common Smart Demystifying Thermostats after reading this article. The article also includes steps on connecting the Thermostat to Alexa and frequently asked questions and a conclusion concerning the same.

Demystifying Thermostat Wiring Colors What Goes Where?

Demystifying Thermostat Wiring Colors What Goes Where

Before you begin any DIY project involving Smart Demystifying Thermostat, take the required measures. Before doing any wiring, make sure all transformers and services are shut off.

Also, make sure the air blower and condenser aren’t connected to the power source. If you plan to replace an existing Demystifying Thermostat, take a photo of the wiring for future reference.

Demystifying Thermostat Wiring Colors

thermostat wiring colors

The demystifying Thermostat wire colors often correspond to the first letter of the termination identification, such as White Wires for Heating, Red Wires for R terminals for Power, Yellow Wires for Y terminals for Cooling, and Green Wires for G terminals for Heating and the Fan.  Brown wires for W2 are the only exceptions Second-stage Heating, Blue or black lines for the C terminal, and light blue wires for Y2 Second-stage Cooling.

1. The color red (r)

Electricity is connected to the R connector. It is normally a red wire extending from the main converter, typically positioned in the air handling unit, for split systems. The transformer, however, may be found in the evaporator coil in some designs. As a result, before performing any wire work on the demystifying Thermostats, turn off the power to the compressor and ventilation system to avoid injury or loss to the equipment.

2. White (w)

The W terminal is often used to heat things. The heating supply can be anything from a typical oil or gas furnace to a more modern boiler or electric heater connected with a white wire.

3. The color red (Rc)

The Rc connector is used to control the cooling unit’s power. The cable from the air conditioning system flows through to the Rc Connector if your HVAC system uses two independent transformers for Cooling and Heating. A jumper can be attached between Rc and Rh if a single inverter powers the Heating and Cooling Systems.

4. The color red (Rh)

The Rh connector, the heating opposite to Rc, is allocated for the heating unit’s electricity. In a single-stage heat system, they are jumpier simultaneously.

Refrigeration is allocated for the yellow (y) endpoint. The Air Conditioning system is controlled by a yellow cable that connects to the compressor.

5. Black/blue (c)

That’s the Common Terminal, and a blue or black wire is normally routed from here to the transformer to complete the circuit and, in some situations, to power the demystifying Thermostat.

6. The color light blue (y2)

The Y2 endpoint is a rare second-stage cooling terminal. If you have a two-stage cooling system (elevated/low values) that needs to be regulated by a sole demystifying Thermostat, link a wire from the second compressor to this terminal.

7. Brown (w2) 

This connector is connected to the second heat source by a brown cable.

8. Green (g)

The connection is green (g) and is used to power the blower. The Indoor Blower Fan is connected to this terminal by a green wire.

9. Orange/Dark Blue (O/B)

Orange/Dark Blue (O/B) is a color combination of orange and dark blue. This terminal is used to power the defrost cycle on heat pumps and can be found on demystifying Thermostats built to work with them. The heat pump is normally connected to this terminal with an orange or dark blue wire.

10. Any Shade (E)

This terminal is designed to provide emergency heating if the heat pump compressor fails and requires some heating. Manufacturers have complete control over the color of the wire that connects this terminal to the backup heat source, which is activated in an emergency.

11. Any Shade (X)

This connection is used for heat pump auxiliary power. While the E terminal activates the backup heat source, this terminal powers it, and the wires for this can be any color, much like the E terminal.

12. Wires that have been shielded (S1 and S2)

These terminals, commonly referred to as T terminals, are used to power Outdoor Temperature Sensors. They usefully separate shielded cables that you can distinguish from other wires right away. They’re insulated to keep electromagnetic interference from interfering with the temperature sensors’ readings.

Steps on how to connect a demystifying Thermostat to Alexa

Steps on how to connect a demystifying Thermostat to Alexa

Tools necessary

  • Demystifying Thermostat.
  • Alexa software.
  • ISP.

i. Create an account with the demystifying Thermostat

First, create an account in the demystifying Thermostat. Creating an account helps Alexa to identify their users. When creating an account, consider generating a strong password and username.

ii. Download and install Alexa software on your android

After creating an account in the demystifying Thermostat, download and install Alexa software on your android device. After downloading the Alexa software, install it on the phone for easy accessibility. When downloading Alexa software, ensure you download the recommended Alexa software with high reviews.

iii. Open the Alexa Software menu

Open the Alexa application menu in the android phone and create an account in the Alexa software. First, open the games and skills in the menu and select the demystifying Thermostat to connect to Alexa.

iv. Sign in to Alexa

Using the credentials in the account creation with the demystifying Thermostat, log into the Alexa software application on your android device.

v.  Establish the connection between the demystifying Thermostat and Alexa

Before adding the demystifying Thermostat to connect to the Alexa, the Alexa first scans the available demystifying Thermostats. Then, after scanning the demystifying Thermostat, Alexa gives out an opportunity to add the available device.

Alexa software has a menu with options for adding new devices. For example, add your demystifying Thermostat by clicking the “adding device” button. Adding the demystifying Thermostat establishes a connection between the demystifying Thermostat and the Alexa software in your android device.

vi. Login to the demystifying Thermostat account

After adding the demystifying Thermostat to Alexa software, log in to the account in the demystifying Thermostat using the credentials in the account creation. Then, allow the demystifying Thermostat to communicate with Alexa and connect successfully.  

vii. Enable the Alexa software to take control of the demystifying Thermostat

Locate the Alexa and enable it to control the demystifying Thermostat. Use Alexa to control the temperature of different rooms while staying in one room.

After connection, Alexa will notify the Android home screen showing the connection in the demystifying Thermostat is successful. The Alexa can still control the demystifying Thermostat using the buttons it has that are on the phone’s screen.

viii. Set up a routine in the Alexa

Use the Alexa to set the daily routine of the demystifying Thermostat so that it can work in case an individual is not available at a time. The Alexa can read and raise or lower the temperature using the speaker in the Alexa so long as the connection between the demystifying Thermostat account and the one with the Alexa is available.

Frequently asked questions:

  • Can you connect the R to the Rh or RH colors?

The demystifying Thermostats exist in different versions. If the demystifying Thermostat is in the latest version and using the latest modem, the red wire can go either in Rh or Rc. But, if you demystify the Thermostat is old, it is inconvenient as it follows only the general rule. Therefore, it is important to choose the best demystifying Thermostat that does not limit you on the wires that can go through other wires.

  • What is the result of connecting the wires incorrectly?

There are several outcomes from connecting a wire incorrectly, and they include the following;

  • Blowing the whole demystifying Thermostat.
  • Occurrence of electric shock.
  • The demystifying Thermostat’s fuse may blow out.
  • Blowing the HVAC elements completely.
  • Increase in replacement, repair or purchasing costs.
  • Fire outbreak, among others.


If you want to connect the wires in demystifying Thermostat, please review the article above and gather a lot of information concerning the colours and know which colours can go through. Understand that each manufacturer uses a different color scheme. Therefore, it is essential to know the model and the version of the demystifying Thermostat rather than assuming that the colours are the same.

Finally, before connecting the wires, there are some precautions you must follow. For example, before you begin any DIY project involving Smart Demystifying Thermostat, take the required measures. Before doing any wiring, make sure all transformers and services are shut off. Also, make sure the air blower and condenser aren’t connected to the power source. Seek help if you are unable to wire the demisting demystifying Thermostat on your own.

Well explained tutorial on wire color codes in this video below Enjoy!

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