An extra unused wire in the wall can be used as the C wire for your new thermostat. The extra wire will also need to be connected to the C (common) terminal at the heating and cooling system. This will provide power to your new thermostat.

Can the C wire be blue?

Blue or Black – C – Common wire, may be unused by your existing thermostat. Enables continuous power flow from the Red wire. Red – R – 24VAC power from the furnace’s transformer.

Where do I connect unused C wire?





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.

What can I use instead of 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.

Is the blue thermostat wire the C 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 if there is no C wire for thermostat?

You most likely have a line voltage system and none of the popular smart thermostats on the market are available to you as-is. (There is some hope with an adapter, but don’t get too excited yet.) This wiring indicates a line voltage system, and you’ll need an adapter or a smart thermostat designed for line voltage.

Where does the blue wire go on a furnace?





Quote from the video:
Quote from Youtube video: Strip. As you can see blue goes into common c right in here under this screw. So in this scenario. The common terminal is going to be right here so if you're installing.

What is the blue wire used for on a thermostat?

heat pumps

The Blue or “C” Wire



C wires or varying colors apply to every thermostat, but blue C wires belong to thermostats attached to a heat pump. Blue wires are for heat pumps, like orange wires. This wire connects to terminal B on your thermostat.

What is the blue wire for?

Blue & Yellow



These two colors are hot wires usually pulled in conduit for common plug-in electrical devices. Blue wires are used as travelers, usually on three- or four-way switches (controlling a light from multiple locations) or as switch legs for things such as fans or lights.

Can I use RC wire as C wire?



No the Rc is the red wire. You need 5 wires or more for this to run with all the functions. You can use one of the other wires but you have to drop control of the fan.

How do you make a C wire for a thermostat?

Quote from the video:
Quote from Youtube video: Run actual thermostat wire in the all and connect. It to the existing thermostat wire if you've got an extra wire or if you want to fish some new ones in the wall. Not a big deal there.

Can I install Nest without C wire?

You can install a Nest Thermostat without a C-wire by using a C-wire adapter, that mimics a traditional C-Wire without you having to wire it.

Does C wire have voltage?



What Is a C Wire? The C wire, a.k.a. the “common wire”, allows a constant flow of 24 VAC (volts AC) power to a smart thermostat. However, the C wire doesn’t provide the actual source of power to the thermostat. The wires that provide the source of power are the R wires (or hot wires).

Does Nest Thermostat E work without C wire?

It may also test to check if the C wire delivers enough power to your Nest thermostat. With a Nest Thermostat E or Nest Learning Thermostat, you’ll need to install a C wire if the thermostat has power issues or its battery often drains.

How much voltage should c wire have?

24v

A C-wire, or a common wire, runs from your low voltage heating system (24v) and carries continuous power to your thermostat.