What is the C wire on a smart thermostat?

What is a C-Wire? A common wire (C-Wire) provides Wi-Fi thermostats continuous power by connecting it to a heating and cooling system (e.g. furnace). C-Wires are required on most Honeywell Wi-Fi thermostats, with the exception of the Smart Round Thermostat (formerly known as the Lyric Round).

Do smart thermostats require C wire?





The good news is, some of the best smart thermostats do not require the power from the C wire to work. In fact, some of the best smart thermostats like the Google Nest Thermostat have no requirement for the C wire as they contain rechargeable batteries or other technology that removes the need for one.

Can Nest thermostat work without C wire?

According to the Nest website, your Nest thermostat will work without a C-wire but specialists still recommend using an adapter if you can’t get a C-wire installed. If your Best thermostat will not receive a constant flow of power, it might not work properly and it runs out of power it will not work at all.

Can I add C wire to 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 use Amazon smart thermostat without C wire?

Pretty much all the best smart thermostats or Wi-Fi-enabled thermostats require a C-Wire connection, since the C-Wire eliminates the need for separate batteries. A modern smart thermostat’s LED display and integrated smart home features requires the device to be powered in some capacity at all times.

Is the blue wire the 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.

How do I install a WIFI thermostat without C wire?

Quote from the video:
Quote from Youtube video: Turn your power to the thermostat off at the circuit breaker. Once you've installed the backplate of your new thermostat onto the wall unwrap the wire if it's wrapped around your wire bundle.

Is C wire required for nest?

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.

Does Nest e need C wire?

The Nest Thermostat E is designed to work even if your home doesn’t have a common (C) wire, but installing a new C wire may be required. If you have a dual fuel system, we strongly recommend professional installation.

Can you use G wire for 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.

Can I install ecobee without C wire?

If you’re lacking a C wire and have at least four wires at your thermostat to work with (refer to this article if you only have two wires), you’ll want to install the Power Extender Kit (PEK).

What color is the C wire?

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.

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.

How do you connect C wire to HVAC?

Quote from the video:
Quote from Youtube video: One of these is gonna be the wires that go to the AC compressor. And they come in through the top here. And they just come down right here through this hole.

How do I know if C wire is live?

Quote from the video:
Quote from Youtube video: Begin by putting one probe whichever probe you want on the rh wire and test every other wire with the other probe. One of the wires will show up is 24 volts and that is your c wire.

Is RC the same 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. It will only come on when furnace comes on.

Where do I connect the C wire on my furnace?

Quote from the video:
Quote from Youtube video: The common terminal is going to be right here so if you're installing. Something you would stick the wire. Into this screw terminal from the bottom.