Whether you have an Ecobee, Nest Emerson or some other smart thermostat, the same principles will apply. The app may also test to check if the C wire can deliver enough consistent power to your Nest thermostat. Even if your old thermostat was not using a C-wire, an unused C-wire may be stuffed in the wall behind the thermostat’s backplate. If it can’t, you have a few choices: Check if there’s an existing thermostat wire you can use as a C wire. Unused C Wire Terminal. Install the New Thermostat. First, you connect wires to the thermostat. Yes, you need an extra wire in the bundle going to the thermostat. If you have a C wire, place it into the C terminal on your wall plate. No, the thermostat does not work with electric baseboard heating, which is a high voltage (120V or 240V) heating system. It provides a constant 24 voltage to the thermostat. In some cases, one of those wires may be your common. If you have a Trane model thermostat, and have a wire labeled X or B refer to your thermostat manual. To install with CWA, you must disconnect the 4 wires from the control board and connect them to the CWA. If your thermostat wires connect to terminals marked R and W, installation is as simple as connecting a third wire to the common on the furnace or boiler's low-voltage Common point. Thermostat Installation & Wiring Diagrams; Installing your ecobee thermostat with the Power Extender Kit (no 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). Label the wires Y, G, R, and W. Note: If you don't have a W wire, the system is still compatible. If you’re upgrading to a smart thermostat, you’ll need to find and identify the C-wire or install a new C-wire. Label and disconnect each wire. In this guide on “thermostat c wire” – we explain everything you need to know about the Common wire, known popularly as the C wire. Do you have a C-Wire? I need a C wire to install a new wifi thermostat. High Performance HVAC on November 24, 2018 at 2:38 am . Basic c-wire introduction. Next, let's talk about the C, or common wire. C-wire help made simple. Just take the extra wire (if you have one) and attached it to the C terminal in the air handler and the other end of that same wire will go to the C terminal on the new thermostat. During initial setup, the app will tell you if you should connect a C wire to your thermostat. If you have C-Wire install it simplifies the smart thermostat installation process. The thermostat may need to be configured to your heating system. The adapter input has 5 wires including a C-wire that connects to the existing furnace wire terminals. Blue wires are also called “C” wires because they are the Common wire. This quick guide will explain what a “c wire” is, what color it could be and how best to install … These letters are standard; hook them up to the same terminals on the new thermostat. Let's take a look at the G wire. If you’ve got a budget of $30, then you can get a decent adapter. In the absence of a C wire, your thermostat battery charges itself by using the power from your HVAC system. This will remove your ability to turn your system fan on, however the fan will still run when your system runs. The Blue or “C” Wire. When you peek behind the cover, you’ll be able to see what you’ve got. The “c” stands for common. Start with the first video and follow along in order until you find the solution that’s right for you. Basic c-wire introduction. Depending on your furnace, this may be either a terminal marked "C" or "Com 24V", or you may need to locate where the common can be connected to. Wyze Thermostat was made to control low voltage (24V) heating systems only. I have to admit, it seems a bit hackerish, but it works! If you can find an unused wire in the bundle of wires behind the thermostat, use it to connect the C terminal and the thermostat. The video below will help you install your thermostat if you do not have a c wire. Snap the thermostat to the mounting plate. Page 8 Connect wires to the C-Wire Adapter Firmly depress the terminal tabs and insert the labeled wires into the “Thermostat” side of your C-Wire Adapter. Check your HVAC control board to see if it has a wire connected to its C terminal. For Sensi™ Smart Touch Thermostat, all system types require a common wire (c-wire). Don’t have a C-wire? Wires Terminals THERMOSTAT This will convert the G into C and Y into K wires at your thermostat. While this is true, it would be advisable to have a C-wire. If the C wire is there, then we use it with the batteries as a backup. A C-wire is just one of the wires that runs from the furnace to the thermostat. The Wyze T-Stat installation video shows C-wire adapter installed (magnetized on the furnace). If you have a fan relay, it will likely be marked G and be green. C-Wire is an power cable that provides current to smart thermostat devices. Do I need to have a C-wire, or “common” wire? The Y and Y2 wires are most likely yellow ones. This is to confirm that your system isn't using a C-Wire. Start with the first video and follow along in order until you find the solution that’s right for you. Thankfully installing a smart thermostat without a C-wire is pretty simple. Alternatively, you can look at the photo from Step 5: is there a wire in the C-Terminal?. Read the installation manual of the new thermostat you buy and wire the device accordingly. You may also check the price of the product in your local market. "We recommend using a C-wire since this is the most straightforward way to provide power to your smart thermostat," Anzalone says. There are many cases where older houses only have the RH and W wire. Remove your thermostat Install without a C wire 3:52. As more consumers install the device themselves, we suddenly need to become electrical experts. Given that you thermostat needs one. The Venstar Add-a-Wire is an inexpensive adapter that turns a four-wire system into a five-wire system.. One more alternative: get a smart thermostat that’s designed to work with systems lacking a C-wire.Check out the ecobee line of thermostats – all ecobees ship with an adapter for C-wireless systems. Reply. The purpose of a C wire is to ensure continuous flow of 24 volts AC power supply to the thermostat. Reply. I had no C-wire, so I was only left with the red, green, yellow and white wires. Here’s a video that walks through the steps on how to install a smart thermostat without a c wire. Screw the system wiring to the screw terminals on the new thermostat using the letter labels as reference (strip the wires back if necessary). C-wire help made simple. Note: The C wire is not needed to complete a thermostat installation. The common wire, sometimes referred to as the c-wire, is what’s responsible for delivering constant power to your thermostat. Venstar Add-a-Wire adapter. YES – This means your thermostat is using a C-Wire, and you don't need to install a C-Wire Adapter. Important: If you don't have a C wire selected in the compatibility checker, switch to the Wyze Thermostat C-Wire with Adapter Installation Guide. Now, it’s your turn to install the new thermostat. You can even use the fan wire to serve as a “C” wire. If there is no C wire, we can use the Smart thermostat with just the batteries. Blue wires are also called “C” wires because they are the Common wire. Yes, the C-wire powers Wyze Thermostat. It is often labeled as “c” on thermostat backplates. What Is The C-Wire? Then you go through the step-by-step setup process and your thermostat is ready to use. There are several ways to add a “C” wire to your thermostat. You can find some really inexpensive C-Wire power adapter on Amazon. The Rh wire connects to the RH terminal on your thermostat. In today's video we are taking a look at how easy and simple it is to install a WiFi Thermostat with or with out a C Wire. What is the C Wire on a Thermostat? The most “meaty” part of installing a new Honeywell smart thermostat, is correctly wiring it up. 10. You may also have up to two black wires as well but these are used for various heating systems in the North or for outdoor purposes, so for most of you these won’t need any attention. I recommend you to buy a 24 Volt C-Wire Power Adapter from Amazon. In this really short video you will learn how to connect an unused wire so it can be used as your C wire, which in a lot of cases has solved the problem of a thermostat not working. Insert the wires into their corresponding terminals as shown below. You can connect as many wires to the C terminal as you'd like as long as you do it in parallel (ie: all wires must terminate on the terminal itself, do not "daisy chain" them). Nest Thermostat can function without a C wire, But if you chooses not to use C wire or dont have C wire while installing, Nest Thermostat can still work, since Nest Thermostat draws power from HVAC system through power sharing to stay connected to power. For Sensi™ Smart Thermostat, a common wire (c-wire) is required for heat only systems, cool only and heat pump systems. Look at the thermostat wiring checklist from Step 8: is the C-Terminal checked? But you do have a gas, oil or propane conventional forced-air system and a wire labeled G. If you use this option, the G wire will be substituted for your c wire at both your thermostat and HVAC system. One common problem when installing a smart thermostat is the lack of a c-wire in your home’s wiring. Substituting a G Wire for a C Wire. The c wire is an extra wire that can be used to provide a return path for continuous 24V power for any application. For Sensi™ Smart Thermostat, a common wire (c-wire) is required for heat only systems, cool only and heat pump systems. Blue – This is your common or “C” wire. Here’s the transformer that I personally like because it has a 20′ cord to reach a far outlet. The four existing wires from existing T-Stat connect to the C-wire adapter output. If your furnace has a C terminal then you can run a new wire from the C terminal to your thermostat. You may also have a W wire, which is likely white, while the E wire is usually brown. A lot of Nest users have had problems when they use the thermostat without a C-wire. This is known as the common wire. If you do not have any loose wire in the bundle, an “add-a-wire” adapter can come in handy. For Sensi™ Smart Touch Thermostat, all system types require a common wire (c-wire). 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