If there is no C wire then you'll need to have the new wiring installed. There are two ways to find out what wires your HVAC system has. When you purchase an item through links on our site, we may earn an affiliate commission. Wire coloring is not standard across all types of thermostats, but these are the most common colors: C wire (blue or black wiring, common for 24-volt power to the thermostat) R wire (red wire for power) R - 24 VAC power from the transformer in your gas furnace. Climate control systems have evolved a great deal in the last several years with the evolution of electronic control. Sometimes it might be a single O/B wire instead of two separate wires. It terminates at your air handler or furnace. Themes, February 13, 2018 /. Whenever you're dealing with something electrical and an important aspect of your home like the HVAC system it's best to trust the pros with the job. The yellow wires connect to the Y terminals on your thermostat. The obvious down side of this is that if the battery goes dead the thermostat will no longer function. For example, if you use a single-stage heat pump with aux heat, the light blue wire will connect to the X (or Aux) labeled terminal. If you're going to upgrade your thermostat it's a good idea to have a C wire installed. 2 wire systems are used for every thermostat and HVAC component out there. These are the standard wires used in almost all modern systems. If youre looking for your furnace to enter a heating mode, the power from the R wire must be powering the heating wire. Reconnect the wires in accordance with either your unit-specific notes from Step 4 or the industry standard color codes. You may use a volt-ohm-milliammeterto do so. https://www.thermostatcenter.com/ is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Henry Tuesday - Copyright text 2017 by SmartHomeLab.net. Copyright 2023 Aire Serv. Finally, we come to the systems that use all 8 wires in the bundle. Your heat pump is connected by the O, or orange wire (if applicable). If you have a smart thermostat like a Nest or Ecobee, the common wire allows your thermostat to constantly change without turning on the heating or cooling or the fan. This Site, including all its Content, is protected under applicable intellectual property and other laws, including without limitation the laws of the United States and other countries. If the wires are incorrectly connected, the system will not operate properly. They provide the source of 24V power that comes into the main HVAC control board itself. 2019 Mathison Air Conditioning, All rights reserved. How to Keep Your Home Safe During the Holiday Season, Possible Causes of Power Loss to a Circuit, How to Add Outdoor Patio Lighting Using LED Tape Lights. Remove the corresponding mounting screws and the associated wires. Thermostat Wiring Explained: An Easy-To-Read Guide for Homeowners. The 5 wire system is the most popular setup. Yellow Wires What All Those Letters Mean on Your Thermostat's Wiring Once secure, push any excess wiring back into the wall and secure the thermostat to the mounting plate. Neighborly can help. You do not want to mix these up. The basics of thermostat wiring and how to replace and troubleshoot it is valuable knowledge for anyone to acquire. Method 1: Look at the wires behind your thermostat. Thermostat Center is supported by our readers. You will typically find 18/5, 18/6, or 18/8 on the label. Don't be worried about hurting it, sometimes it takes some doing to get the faceplate off. Knowing what each letter stands for and what its used for can help you figure out which wire goes where on your new thermostat. The other wires on the panel connect the circuit so the loop carries power back and forth to the board. The W terminal the one that triggers the heating. Causes, Troubleshooting & Fixes. That control can be digital or analog, but it all ends up going through the thermostat wires. However, an installer may have used any color when installing the wire to the W2terminal. Orange This wire connects to your heat pump (if you have one). Using the photo you took earlier, attach the wires to the correct terminals as they were before on the new thermostat. With an air conditioner, you dont have the heat control, so you will use a yellow wire to control the cooling and green for the fan control. In this article, Ill explain the wiring of a thermostat as well as how to replace a thermostat. Room thermostat installation & wiring guide: this article series explains the basics of wiring connections at the thermostat for heating, heat pump, or air conditioning systems. Only use this manual as a reference. If you are replacing an old thermostat with a new digital thermostat, the electronics in these units may need yet another wire for a terminal labeled C. A cooling system with two compressors or a two-stage compressor need a Y2terminal, so the thermostat is able to control the second stage of cooling. All Rights Reserved. The number after the slash is how many wires are in the bundle. 4 Wire systems are becoming more common due to the popularity of heat pumps, which use a fan, heat, and cooling to operate and keep your home at the right temperature. That control can be digital or analog, but it all ends up going through the thermostat wires. Our professional HVAC specialists can handle installing your C wire and your whole new thermostat setup. It terminates in your outdoor condenser for reversing valve operation from hot to cold. White The white wire is what connects to the (auxiliary) heat on your system. It will also give you a custom wiring diagram that you'll need for installation. If you're considering upgrading your thermostat is that something you can do yourself? Feeling too cold? However, many homeowners are intimidated by the complexity of thermostat wiring. In this diagram, you will notice two extra wires (black) that connect separately to external sensors. Note: This post was originally published on June 27, 2019. Based on the application, the O and B wires may be linked in parallel or in series. Yellow The yellow wire connects to your compressor. The other wires on the panel connect the circuit so the loop carries power back and forth to the board. The orange wire only applies to homeowners with an air-source heat pump. Most of the process is about following safety procedures and avoiding common mistakes. This information is designed to help you understand the function of the thermostat to assist you when installing a new one, or replacing or up-grading an old one. G: This wire controls the blower fan, which is responsible for pushing the warm or cool air through all the vents in your house. You'll need to check your current thermostat's wires to tell if your system is Nest thermostat compatible, and which thermostat models it will work with. A typical setup will use red, white, yellow, green, and blue. Plus, Im anything but a technician so what I have detailed below is here purely as a guideline. As I licensed, journeyman electrician, I have pretty high expectations for a DIY resource. In this article, I am going to explain the function and wiring of the most common home climate control thermostats. 10/19/22 Known as the common wire, (C-Wire) provides Wi-Fi thermostats continuous power from heating (e.g. If you have a clipped thermostat, just pull it out. The control wires, though, are standard for all 6-wire applications. Below are the common thermostat wire colors: The white wire underneath your thermostat connects to your heating system. Green wire, connected to the G terminal, is for fan control. Each location is independently owned and operated. Since furnaces only use two wires for power and operation, smart controls cannot function properly without the extra wire. It's best to get the correct equipment installed even if it costs a few extra bucks. Whether you have a simple 2-wire system or a more complex 8-wire system, thermostat wiring doesnt have to be difficult. The four-wire thermostat has four wires included (red, white, green, blue) A four-wired thermostat is used for heat pumps and HVAC (heat and cooling). Find all Question with images of the schematics, wiring diagrams and technical, 38 Wiring Diagram Ezgo Gas Golf Cart Background, Get Arduino Circuit Schematic Maker Background. HVAC Control - Heat Pump Systems Air Conditioner Thermostat Wiring Details and Color Code R Terminal is Connected to the Red Wire or R Wire - this is 24-volt power for the thermostat and controlled devices. by Chris Woodford. You just need to find out the wire selection. If you have an RH and RC, then you must place a jumper between R and RC as well as one for R and RH. Whether youre trying to fix your thermostat, or installing anew smart thermostat, this thermostat wire color code will help youtoavoidDIYwiring problems. Sometimes it can be difficult to distinguish between the white and yellow or dark blue and black wires. The C wire is an extra wire that is used to create a continuous 24V power loop between your thermostat and the rest of the HVAC system. Carrier Thermostat Reviews: Price Analysis, Buying Guide & Comparison, Ecobee vs Nest Thermostat: The Ultimate Comparison Guide, Lennox Thermostat Reviews: Price Analysis, Buying Guide & Comparison, Nest Thermostat Reviews: Nest 2nd generation vs. Nest 3rd Generation vs. Nest E, Troubleshooting Honeywell Thermostats: Top 4 Most Common Problems with DIY Solutions, Thermostat Wiring Explained: How To Wire And Install A Thermostat, Trane Thermostats Reviews: Prices Analysis, Buying Guide, & Comparison, Thermostat Wont Change Temperature: Causes, Troubleshooting & Fixes, What is C-Wire? This brings in the 7th wire. While it's technically possible to run a system without one it's highly inefficient. Red wire to the R terminal with an R RC jumper installed. Once you have identified which wire is used for the C wire, connect this to the C terminal on the thermostat. You definitely need to consult the manual for your HVAC (where the other end of the wires connect) and look at where they attach on that board. If you are not a qualified technician then I would say try to get a qualified technician who can do it properly. The yellow wires underneath your thermostat connect to your compressor. Replacing a thermostat is really easy, but sometimes the terminal letters on your old thermostat dont match up with the ones on your new thermostat. furnaces) and cooling systems (e.g. (Its important todetermine that your heat pump is compatible with your thermostatbefore you decide.). Not anymore! HVAC topics can be tricky for homeowners so I decided to share my knowledge on the subject. This sites design and content are proudly supported by SIFT SEO & Content. Select your thermostat below: Does this mean this thermostat wont work? How to Wire a Thermostat | Honeywell Home It can be difficult depending on the type of system you have and how complex it is. Keep in mind, if youre not sure how towire a thermostat, your system could run improperly or even worse. The common wire, sometimes called the c-wire, is responsible for delivering constant power to your thermostat. Take a flashlight and check it out to see if you see any unused wires in there. You want to have a thorough understanding of the thermostat before you begin working. The connections are often created as follows: Normally, terminal 01 serves as ground and connects the 12-volt neutral system of the camper via a black or blue cable. The E terminal is for emergency heating, which occurs when the system runs completely on the second stage heat source. ), However, the terminals of the thermostats of today are still labeled the same, and provide the same functions as what we have discussed thus far. This is found on more complex heating systems like central heaters and boilers. Less common will use dark blue and brown or even black. 2023 Neighborly Company and its affiliates. C: This stands for the common wire in an HVAC system, and it provides power to the thermostat. The white wire is for heating and is connected to the W terminal on the thermostat. For starters, a furnace system doesnt use supplemental heat and offers zero cooling options. Using 7 wires is pretty uncommon, and it details a system with a lot of components. Typically, a furnace plus A/C HVAC system has four or five thermostat wires and a common wire. A yellow wire connects your air conditioning compressor called the Y wire. Patch the drywall to ensure a tight fit when installing your new thermostat. To purchase a c-wire adaptor: Click Here. I appreciate it very much as it helps me keep making these videos for you.Blessings,Ben Below is a guide to the most common method, butyour system may not follow the same code. This information should help you see how to connect it. As shown in the diagram, you will need to power up the thermostat and the 24V AC power is connected to the R and C terminals. How do you know if your system has a C wire? Heat Pump Thermostat Wiring Explained! Emergency heat is only used if theres a problem with your heat pump. A heat pump system, on the other hand, has eight or more different thermostat wires. Checking the labels for the wiring in your thermostat is the easiest way to figure out if you have a C wire. If, for example, you have an R wire and an Rc wire, the R wire controls the heating system. The white wire underneath your thermostat connects to your heating system. Thermostat Wiring to a Furnace and AC Unit! Color Code, How - YouTube Removing and replacing the thermostat is the same in all the processes (two, three, four or wires). With a little bit of knowledge, anyone can tackle this common DIY project with ease. A Full Guide To Thermostat Wiring: Types and Color Coding In the central heating and air system (the most common type), you will use all five wires for power, heating, cooling, and fan, with an optional common wire for smart controls. In addition to the WiFi signal, most modern thermostats have a beautiful large and full-color touch screen. Remove the thermostat from the mount to expose the wires and terminals. What's the Difference Between Thermostat Wire? - Jackson Systems Step 2: Remove the thermostat from the base. When the fan on setting is selected, the contacts between R and G are closed turning on the relay that powers the blower motor directly regardless of a call for heating or cooling. PDF Thermostatic Wiring Principles It is always advised to buy 18/8 wire, though. So what the R wire does with the C wire is it creates a circuit that can charge the battery without activating anything additional. On the other hand, if you have a reverse valve cooling system, attach the orange wire to the O terminal. No rules are implemented that require all HVAC equipment to follow the same color coding method. You should consult a licensed electrician if you have any questions about the wiring for your thermostat. A c-wire connection and lead might be discovered. Here is the industry standard color code for thermostat wires used for most systems: The W wire is connected to your heating system. The most common systems' thermostat wires follow the following industry-standard color scheme: Your heating system is connected to the W wire. Make sure you can see the terminals and the wire colors easily. So I have 4 wires and in my old thermostat they were hooked to g y w and rc and then there was a free wire and one end went into rc and the other into the. When wiring a heat pump, AC system, or furnace, the wire colors and set terminals are essentially the same. If the system had two-stage heating, and/or cooling, the 2nd stage termainals would be labelled W1 and W2 for heating, Y1 and Y2 for cooling. Always double check to ensure all the power is off, and there isnt any voltage. However, for some heaters, this is a major issue because it's like it is being turned on and then off multiple times per day. Article by: Its usually black, but in some cases, its the thermostat blue wire. Prior to getting involved in this project, you should always read the thermostat manufacturers instructions. The red wire is for powering the system, which is connected to the 24v power terminal. You can use the fan wire as it's own C wire. Yellow - The yellow wire connects to your compressor. The O wire reverses the valve from heating to cooling, and the B wire switches the valve from cooling to heating. The Orange Wire is for the reverse valve cooling, and the Dark Blue/B Wire is used for reverse valve heating. We look forward to meeting you soon! The color of wire R is usually RED and C is BLACK . Posts/videos may contain affiliate links. While technically the colors dont matter, it is important to stay with convention to avoid confusion later. If you open up your thermostat, you will see some wires connected to labeled terminals inside. Thermostat Wiring Colors & Terminals Explained - SmartHomeLab.net Basic Thermostat Wiring Diagram Explained - YouTube Tape the wire bundle to the wall. No thermostat equals no AC or heat. A majority of the time, the HVAC wiring color is brown for this particular terminal. You can connect your new thermostat using that as your guide if they do. And consult your HVAC and thermostat manuals for wiring diagram information if youre not quite sure which wire goes where, or what configurations your HVAC system supports. A secondary heat source located in the air handler will kick on. Instead of pulling from the central power of a C wire the Nest uses your system itself for power, as long as it remains running. Step 2: Now you need to check which wire goes into which socket or do you have a different color code than the universal ones. What is a C-wire and why do smart thermostats need one? Most Common Thermostat Diagrams 1 Heat / 1 Cool Thermostat Furnace and AC Look behind the thermostat to see if your electrician or the installer tucked a c-wire into the wall. Apr 26, 2020 Sometimes this is easy and sometimes it's harder depending on the model of the unit. Orange goes to the O terminal for reverse valve cooling, yellow to the Y terminal for AC cooling, and green to the G terminal for fan control. O, B, O/B: These wires are responsible for switching the changeover valve in a heat pump system. Each of these needs to be controlled by a thermostat and its wires. How to Wire a Thermostat - The Home Depot When you need to wire a new thermostat or install a new thermostat from scratch, it can get confusing. From your furnace, you're getting anywhere between 18 and 24 volts, depending on your system. Thermostat Wiring Explained (with or without a C wire) - YouTube The white wire connects to terminal W in industry-standard thermostats. Turn your current thermostat to the OFF position first. The Rh wire connects to your heating system as opposed to your cooling system. Do you want to risk that happening while you're away from the house? Youll usually find two-stage heating in locations where people experience extremely cold winters. Detach your thermostat from the wall and look at the wires connecting to it. It's a simple enough switch and install. The yellow wire is used for a cooling system. Thermostat Wiring Explained - Electrical Online We will focus mainly on the basics of home heating / cooling thermostats, and first of all, I will explain the function of them. It's actually pretty interesting in my opinion!You can support the channel by using one of the able affiliate links whenever you shop (even if it is for something other than what is linked) at NO cost to you! Step 4: Now connect all the wires to the new thermostat and check every option to ensure its working. (cooling, heating, fan, etc). Our page top sketch, courtesy of Honeywell Controls, illustrates the wiring diagram for a traditional Honeywell T87F thermostat used for 2-wire single pole single throw . a high level for extremely hot or cold days, and a low level for mild days). In almost all cases, the common wire is either blue or black. The installer could have used any color, though. If you purchase a product through an affiliate link, your cost will be the same but Electrical-online will automatically receive a small commission. But, in this new age of heightened technology, smart homes, and fancy touchscreen displays your thermostat needs a constant source of power. You will either need to run a new bundle, a single wire, or use an adapter kit. Thermostat Wiring for Dummies - How Anyone Can Do It You can get kits to create a c-wire without running a new wire bundle if needed, and Honeywell makes them available with every thermostat they sell. A majority of brands use the orange wire for the reversing valve while a small percentage use the dark blue for it. Honeywell Heat Pump Thermostat Wiring - Plumbingpoints In accordance with your wiring schematic, connect the thermostat terminals with the stripped harness wires. In many electrical systems, the universal color of this power wire is red. If you have any doubts,getaprofessional thermostat installation. Here we tell you everything you need to know about the thermostat C wire and the basics of thermostat wiring so you'll no longer be in the dark. Sometimes after replacing the thermostat, people forget to put a jumper in between these twothis could result in heating and cooling not working. The color of the wire varies from installer to installer, but it appears light blue is usually the go-to color for this terminal. That wire tells your furnace to turn on a cooling mode, which is what the Y wire controls. Regardless if you have heating or cooling already, when you activate that system, it will turn on your fan no matter what. Heat Pump Thermostat Wiring Diagram. If you need to patch the wall or paint behind the old thermostat, now is the time. That 24V will be coming through the power wire. The brown wire connects to the Y2 terminal for the two-stage heating system, while the white wire goes into the W terminal for heating control. | Powered by WordPress. Thermostat Wiring: The Fan Wire (G/Green Wire) The yellow wires terminate at your compressor contactor via an air handler. It has to be turned on manually, whereas auxiliary heat can turn on automatically if need be. It alters the heat pump cycle from heating to cooling and vice versa.