Option 1: Add a C Wire to Your Furnace.
- Turn off the power to the furnace and thermostat at the circuit breaker.
- Make sure the power is off by trying to turn the thermostat on.
- 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. This may take a little work depending on how far the new thermostat is ...
- Connect the wire to the C terminal at the thermostat.
Full Answer
Can you use a stranded wire for a thermostat?
You can use pretty much any wire you like for a thermostat as long as it is thick enough. Many newer thermostats will only accept at the thickest, 16 gauge so the ends may need to be trimmed to fit in the socket. Solid or stranded doesn't matter. Besides, what kind of wire do you use for a thermostat?
Does my thermostat have a "C" wire?
Usually “C wire” or the Common Wire will be a blue coloured wire. But there is no particular standard for thermostat wires, so it can be any color like Yellow, Brown, Green or any other color. If you see a wire of different color, say Yellow in the ‘C’ terminal of your current thermostat, most probably it should be your ‘C’ wire.
How do you know if the thermostat is good?
- Make sure the inside of the thermostat is clean.
- Check if the thermostat box is level, since being off-center can alter the accuracy of the internal component.
- Check your box’s location, since placement in direct sunlight or in front of drafty windows and doors can greatly affect correct temperature regulation.
How to reconnect WiFi on your thermostat?
- Press the Menu button to open the menu. FAN MODE is displayed.
- Press the down button until > NETWORK is displayed.
- Press the Mode button to enter the NETWORK menu.
- Press the Mode button again to start WPS.
- Press the WPS button on your router.
- The thermostat should now be joined to your Wi-Fi network*.
How do I find the C wire for my thermostat?
0:374:38How to Tell if Your Thermostat Has a C Wire - YouTubeYouTubeStart of suggested clipEnd of suggested clipLikely there is gonna be a fifth wire tucked into the wall I'm thinking that's going to be our CMoreLikely 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.
What to do if there is no C wire for thermostat?
0:202:52What if I Don't Have a C-Wire? - YouTubeYouTubeStart of suggested clipEnd of suggested clipTerminal. If there's already a wire attached to the C terminal. Just leave it be and attach a newMoreTerminal. If there's already a wire attached to the C terminal. Just leave it be and attach a new wire next to it go ahead and push all the wires back into the wall. And close the backplate.
Do I need the C wire on a thermostat?
Yes, you should install a C-wire if you are upgrading your thermostat. Nearly all modern thermostats, smart or not, require a power source, and that doesn't look likely to change any time soon.
How much does it cost to install a C wire in a thermostat?
If you plan on replacing your existing thermostat with a smart thermostat, you likely need to install a C-wire, which will cost somewhere between $120 and $200 to install. A C-wire provides your smart thermostat with constant power, enabling a continuous Wi-Fi connection and screen display.
Is RC the same as C-Wire?
The C and Rc wires are not the same. To install this thermostat you should follow the exact same wiring of the previous thermostat.
What color is the C-Wire?
Blue wiresBlue 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.
Where is the C-Wire on an old furnace?
3:045:28HVAC Furnace Has No C Terminal? - YouTubeYouTubeStart of suggested clipEnd of suggested clipThe wire coming from outside from the condenser unit is only going to have two wires a red and aMoreThe wire coming from outside from the condenser unit is only going to have two wires a red and a white looking like this. And those two are going to go to y. And c common on that terminal strip.
Can I use the G wire for the 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.
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.
Does Honeywell thermostat require 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 all smart thermostats require a 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.
How do you use a C wire adapter?
0:566:31How to install TrickleStar C-Wire Adapter - YouTubeYouTubeStart of suggested clipEnd of suggested clipBoard once all wires have been removed and labeled it's time to attach the trickle star c wireMoreBoard once all wires have been removed and labeled it's time to attach the trickle star c wire adapter connect the disconnected wires from the control board to the c-wire adapter. As you insert each
Where is the C-Wire on an old furnace?
3:045:28HVAC Furnace Has No C Terminal? - YouTubeYouTubeStart of suggested clipEnd of suggested clipThe wire coming from outside from the condenser unit is only going to have two wires a red and aMoreThe wire coming from outside from the condenser unit is only going to have two wires a red and a white looking like this. And those two are going to go to y. And c common on that terminal strip.
Does Amazon thermostat need C-Wire?
Amazon Smart Thermostat requires a C-wire or a power adapter kit. Use the compatibility checker to see if your home has one already. Guided installation instructions are included in the Alexa app.
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.
Does Honeywell thermostat require 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).
How to connect thermostat to AC?
There are several steps you need to take to connect your thermostat to your AC unit: Disconnect the thermostat. Label your wires. Familiarize yourself with the color coding for the wires. Check the wires. Connect the wires from the control board to the outside unit.
Where are the yellow wires on my thermostat?
The yellow wires located underneath your thermostat are connected to your compressor and control your air conditioning system. They connect to the Y terminals on your thermostat and end at your compressor contactor through an air handler.
How Does the Contact Terminal Operate Your Air Conditioner?
The two wires that you attached to the contact terminal sends power through the terminal’s coil. The coil will draw 24 volts from the control board, which will suck a plunger in on the contact.
How to tell if thermostat is bad?
There are several ways to tell if your AC thermostat is bad: 1 No power in your thermostat 2 Your AC or heater won’t turn on. 3 The heater or air conditioner continually runs and doesn’t turn off.
What happens if you don't read thermostat labels?
Ensuring that you read all labels will help this process to go smoothly. If you don’t pay attention to the names, you may hook your thermostat up incorrectly.
How to keep cable from falling back into wall?
Also, when you disconnect the wires, you should spread them out. Spreading the wires keeps the large cable from falling back into your wall. If the wires fall into your wall, you will need to fish it out or cut a hole to get them out.
What happens when you remove a thermostat?
When you remove the thermostat, you will notice wires coming from out of the wall. These wires will be connected to the base. Before you disconnect everything, it’s a good idea to have labels, so you remember where everything goes.
What If There Is No C Wire For Thermostat?
Before you do anything, make sure the C wire is missing. Some people have C wires, but they don’t know how to identify them. Follow these steps to find the C wire:
Do All Smart Thermostats Require A C Wire?
Ordinary thermostats don’t require common wires. Smart thermostats need C wires because their Wi-Fi connectivity consumes too much power, not to mention all the other functions they possess.
Can I Use Other Wire As A C Wire?
If you don’t have a C wire, you can use a G wire as a C wire. But this wire controls the fan independently. If you use the G wire as the C wire, you cannot run the fan independently in situations where the HVAC’s heating and cooling systems are not operating.
Do Thermostat Work Without C Wire?
Ordinary thermostats will work. They have batteries. Smart thermostats could also work. But smart thermostats use a lot of power. They can’t rely on battery power to operate.
What is the C wire on a thermostat?
The C wire completes the circuit from the R wire back to the HVAC system’s control board. This is what provides the continuous flow of power which keeps the smart thermostat’s display and Wi-Fi capabilities running 24/7.
Where is the thermostat wired?
The thermostat is wired directly to the furnace and not to a zone panel
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.
What Color Is a C-wire?
The C wire’s color isn’t standardized, so its color can’t be guaranteed across all HVAC systems. It is most often either blue or black, unless the installer did their own rewiring to create a C wire.
How to connect a C wire to a furnace?
If your furnace and new thermostat have a C terminal, you can simply run a new wire between your furnace and thermostat. Turn off the power to the furnace and thermostat at the circuit breaker. Make sure the power is off by trying to turn the thermostat on.
How to tell if thermostat has C wire?
Checking the labels for the wiring in your thermostat is the easiest way to figure out if you have a C wire. If you open up your thermostat, you will see some wires connected to labeled terminals inside.
What is the name of the wires that provide power?
The wires that provide the source of power are the R wires (or hot wires). They are labeled R h (for heating), R c (for cooling), or R h/c (for both heating and cooling). Some thermostats simply have one wire labeled R.
How to tell if your thermostat has a common wire?
Examine Backside of your Current Thermostat. The easiest way to know if your home wiring already has a common wire is to examine the backside of your current thermostat. To do this examination, you may remove the face plate and take the thermostat out of the wall.
What color wire goes into a thermostat?
In the above image, a “Blue” coloured wire is coming into terminal marked “C”. Usually “C wire” or the Common Wire will be a blue coloured wire. But there is no particular standard for thermostat wires, so it can be any color like Yellow, Brown, Green or any other color.
How many volts does a thermostat need?
Thus modern thermostats require a continuous power supply and the C wire or Common wire is required for most thermostats to ensure 24 volts AC supply continuously. Note: You might be thinking the R wire ...
What is the color of the C wire on a furnace?
C wire from furnace circuit board going to thermostat – source. If you observe the terminals, you can see two wires are tapped from ‘C’ terminal. The ‘black’ color wire is part of the set that goes to the thermostat. The ‘white’ color wire is part of the set that goes to the condenser unit. In another image given below, you can see ...
What is the difference between a C and R wire?
Well, the R wire is a power source but it does not ensure a continuous supply when the furnace is OFF. 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.
What color wire is connected to the C terminal?
Yellow color wire connected in ‘C’ terminal – Source. In some cases, your old thermostat may not have a ‘C’ terminal. In such cases, there are chances that a ‘C wire’ is already in place but left unconnected. Look for any wire that is tucked away behind your thermostat.
What to do if you don't have a C wire?
If you don’t have a C wire running from the furnace, you’ve the following options. Install a new C wire. Use a C wire Adapter. Choose a thermostat that doesn’t need C wire or has an alternative solution.
