If you pop off the cover, you will see a wire marked with a “C.” Technicians often refer to this blue wire on thermostat as the C wire or “Common” wire. The C wire connects to the power source, typically a low voltage or 24 volts AC (24 VAC).
What is the blue wire in AC?
The blue wire, or C-wire, is known as the common wire. It’s there to provide power to the thermostat. Older thermostats usually don’t have a C-wire because they either don’t need power or, if they do, they get it from a battery. Modern thermostats are a different story.
Can a blue wire be AC wire?
The Blue or C Wire
Blue wires are also called C wires because they are the Common wire. C wires are necessary for any smart thermostat that needs to be connected to a power source 24/7, regardless of your heat pump type.
What is a blue thermostat wire for?
These wires are also called “C” wires because they’re known as the common wire. This wire allows the thermostat to connect to a power source constantly. Blue “C” wires are most common in thermostats that connect to your heat pump. This wire must connect to the B terminal on the thermostat.
Where does Blue C wire go on furnace?
Quote from the video:
Quote from Youtube video: You would typically connect. This a/c wire to be the C terminal on the board on the control board on in the furnace.
Where does the blue wire go?
The blue wire from the ceiling fan gets connected to the second live wire from the ceiling. This second wire can vary in color but is most commonly red or black. This connection allows you to power your lights from the second switch.
What color is a C wire for thermostat?
blue
For the thermostat to work properly, the red wires must be connected to the correct corresponding terminal. The C, or common wire, provides smart thermostats with continual power. It’s usually blue, but it may also be black, brown or purple.
How do you hook up a C wire to a furnace?
Quote from the video:
Quote from Youtube video: You would just look where the c wire goes or where the wire from the air conditioner goes to the c. And that is going to be your 24 volt. Common.
Is RC and C wire the same?
Hi there! The C and Rc wires are not the same. To install this thermostat you should follow the exact same wiring of the previous thermostat.
How do you identify C wire?
Quote from the video:
Quote from Youtube video: Likely there is gonna be a fifth wire tucked into the wall I'm thinking that's going to be our C wire most likely because as you can see we have a green a yellow a white in a red.
Can I use G wire for C wire?
Option #3: Use a G-Wire as a C-Wire
If there is no hidden C-wire, you can use a G-wire instead. However, you will not be able to use your fan independently when the heating or cooling isn’t running. Also, many HVAC systems are incompatible with this solution, including: HVAC systems using electric heat.
How long is a strand of C wire?
Blade size: length=65 mm, width=21 mm. Spacing of blades: 100 mm C/C. Coil diameter: 3′-2″ or 960 mm.
Is the C wire a ground?
C stands for common. The common wire is the ground or negative wire. To complete the circuit that provides power to the thermostat you need a positive and negative wire from the 24V transformer.
Is the C wire hot or ground?
Typically, the wires that provide the power (often called the “hot” wires) are labeled Rc (cooling) and Rh (heating).
Where do you connect the C wire?
Option 1: Add a C Wire to Your Furnace
Remove the access panel from the furnace and locate the thermostat wires and terminals. Connect an 18 AWG wire to the C terminal at the furnace. Next, remove the thermostat face plate. Now, run the new C wire from the furnace to the back of the new thermostat.
Is the C wire a neutral?
The C wire is more like a neutral wire (in electrical terms) and it completes the electrical circuit between the furnace (or any heating system) and the thermostat, thus ensuring a flawless power supply to thermostat even when the furnace is OFF.
Can you connect C wire to transformer?
A C wire transformer has two output wires; connect one wire to Rc terminal and the other wire to the C terminal of your thermostat. Once you finish this connection, plug the transformer into your mains power outlet. The installation is complete now and the thermostat will be powered upon switching ON the power outlet.
