blue.
The blue wire on the thermostat is the Common or C wire.
What is the common wire on a thermostat?
C wire
The C wire, or common wire enables the continuous flow of 24 VAC power to the thermostat. Technically speaking, power flows from the R (red) wire, but not continuously (not on its own, anyway). To make it continuous requires a common wire to complete the circuit.
What color wire is C?
Blue wires
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 do the colors on thermostat wires mean?
This is the most typical thermostat wiring style, and it applies to systems that regulate both heat and air conditioning. The wires are typically arranged as follows: red for 24-volt hot, white for heat, yellow for cooling, green for the fan, and blue for common (although the common wire may be a different color).
What color do you use for common HVAC?
Thermostat Black Or Blue Wire (C Wire)
The black wire or blue wire (either color is used) is the C Common wire.
What is meant by a common wire?
The common wire is normally the white wire, at least in the United States, and is often called the neutral wire. It’s also called common because all circuits in the house typically have the white wires tied together, which means every circuit has that wire in common.
How do you identify C wire?
It is easy to see if you already have a c-wire connected to your system. Simply remove your current thermostat face from its baseplate and look for the terminal labeled with the letter c. If this terminal has a wire attached to it, you have an active c-wire.
What if there is no C wire for thermostat?
If you don’t see a wire you can identify as the C-wire, though, don’t despair yet you may need to look behind your existing thermostat. If your current thermostat didn’t need a C-wire, it (or a wire that can be used as a C-wire) might be rolled up inside the wall.
What is the Y2 wire on a thermostat?
Y2 is the thermostat wire for second stage of cooling. Y wire is for the first compressor (air conditioner units) and Y2 wire is for the second compressors (air conditioner unit). Y2 wires apply only if you have two air conditioner compressor units running from one AC thermostat.
Is common wire hot or ground?
The “common” is the “neutral” or “ground” wire, depending on the type of circuit. In normal US residential wiring, you’ll have a black “hot” wire, a white “neutral” or “common” wire, and a green or bare “ground” wire.
Is common wire load or line?
In a 3-way configuration, the “Line” wire should be connected to the “Common” terminal of the Brilliant Control. Load Wire: This is the wire that connects your switch to your light bulb or other load (ie: a fan or other appliance). It is also usually black.
What wire is the common wire?
Black wire: This is a hot wire that carries electricity from the power source to the first switch in a typical 3-way setup. It’s also called the common wire or the line wire. Unless the breaker is off, this black wire is always hot.
Can you 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:Two-wire heat-only HVAC systems.
What does G mean on thermostat?
G: The G terminal controls the fan relay and is responsible for turning the blower fan on and off automatically or manually via the thermostat. RC: The RC terminal is the 24-volt cooling power supply.
What color is Y2 on thermostat?
Yellow
Thermostat Wiring Color Code Chart
| Marking | Wire Color Code | Description |
|---|---|---|
| W | White | Primary heat cell relay |
| E | Brown | Emergency heat relay |
| Y | Yellow | Primary cool call relay |
| Y2 | Yellow | Secondary cool call relay |
What are S1 and S2 wires on thermostat?
L: This terminal is designated for indicator lights on the thermostat, sometimes for when auxiliary or emergency heat is turned on, or if there’s a general problem with your system.S, S1, S2: These wires run directly outside and provide outdoor temperature information to the thermostat.
What does Y1 and Y2 mean on a thermostat?
Y/Y1 and Y2. In conventional cooling systems, Y/Y1 controls the first stage of cooling and Y2 controls the second stage, which helps cool down the home faster. In heat pump systems, Y1 controls your compressor, which heats and cools your home.
Is common wire white or black?
Red, Black, and White are the colors of switch wiring for three-ways. Red and Black are connected to the switches if the White is used for neutral. The White is often referred to as Common, but the colored wires are also used as hot wires.
What is the difference between a common wire and a hot wire?
Among all these wires, neutral wires are often known as common wires.So, they call it the common wire to distinguish neutral wires from hot ones. In circuits, hot wires represent the source of electricity and the start of a circuit. It always carries electricity and should never be touched.
What does common mean on the back of a light switch?
A one way light switch has two terminals which is a common marked as COM or C. The common is for the live wire that supplies the input voltage to the switch. The other terminal is marked as L1 and is the output to the light fixture.Manufacturers don’t make decorative one way switches.
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