Thermostat Wiring Explained: An Easy-To-Read Guide for Homeowners. A C-wire, as covered earlier, can be either blue or black. For full thermostat wiring assistance: Click here. However, please note that this is a list of common wire colorsusedandyour thermostat maycontaindifferentcolored wires. O, B, O/B: These wires are responsible for switching the changeover valve in a heat pump system. My name is Josh and I am obsessed with DIY and improving my family home. Itll easily come out. C-wires are necessary for programmable and smart thermostats to program a heating or cooling schedule. Finally, the two-stage heating system uses the brown wire to the Y2 terminal. Green - The green wire connects to the fan. 10 Most Common! 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. However, armed with the proper information you must have to work safely and completely, home owners like yourself CAN complete most simple home wiring projects. Jerilyn Brown - What I would like you to know is the information detailed below is based on the industry standard, yet not all thermostats will work this way simply because letters and numbers are used as well as color. Thermostat Wiring Explained A look at thermostats and climate control within the home for heating, Air Conditioning, Fan auto/on, terminal labels, wires needed and more. This takes a lot of power. document.getElementById( "ak_js" ).setAttribute( "value", ( new Date() ).getTime() ); SmartHomeLab.net 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. Restart the main breaker for the HVAC system. We hope this article has explained what a thermostat C wire is, why it's important, and why you need one for the modern smart thermostats. Usually, you just remove your thermostat's cover and enter the wires you find into the compatibility checker. A look at thermostats and climate control within the home for heating, Air Conditioning, Fan auto/on, terminal labels, wires needed and more. 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. You can use the fan wire as it's own C wire. Related Article How to Reset an AC Thermostat. Reconnect the wires in accordance with either your unit-specific notes from Step 4 or the industry standard color codes. Detach your thermostat from the wall and look at the wires connecting to it. For instance, you could cause a system failure, damage to your devices or a blown transformer or a fire. The first 5 wires are the standard, as we have discussed above. No thermostat equals no AC or heat. Not sure about doing this type of projectyourself? Air Conditioning systems). If your HVAC system has multiple heating stages, then you may find more than one white wire. If you are not a qualified technician then I would say try to get a qualified technician who can do it properly. Starting on the right side from top to bottom, we have the common connections. I hope this article helped with your question about thermostat wiring. However, because running new wire is difficult on a finished home, a c-wire can be any color of unused wires at the thermostat. For example, if a 5-wire system is already wired, the orange wire may be used for the common wire. Pull the wires through the backplate's hole on the thermostat. The W wire is the heating wire. But when I go to the house for repair, it's just an insignificant error done while replacing the thermostat. For emergency service please immediately call us for assistance. What To Do If I Dont Have a C-Wire? You may be thinking all of that sounded really complicated and unnecessary but, the fact of the matter is, thermostats have come a long way from the mercury blob moving a needle of yesteryear. You have to understand that wire colors are not standardized. To request service, please select your preferred appointment date and time below. All rights reserved. 6 wire setups include using the C-wire and will be used on advanced heating systems with air conditioning. 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. Finally, the black wire is used for the C-wire or common terminal connection. You dont want it to fall back into the wall while you are removing the mount. Always refer to your instructions when wiring up a system to ensure you are wiring to the manufactur. C wires or varying colors apply to every thermostat, but blue C wires belong to thermostats attached to a heat pump. A typical setup will use red, white, yellow, green, and blue. This additional terminal is labeled G in the thermostat. 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 . In this diagram, Trane covers the use of all 8 wires in a typical 18/8 bundle. Make sure you can see the terminals and the wire colors easily. 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. The control wires, though, are standard for all 6-wire applications. You do, in fact, have a c-wire, but you need to locate the lead's end close to your thermostat. It can be difficult depending on the type of system you have and how complex it is. If you are rewiring an entire system running a new wire bundle is the best option. Keep in mind, the color of the wire doesn't always signify a connection to the same color on the board. We look forward to meeting you soon! If your system requires 7 or 8 wires, then 18/6 will not work for you. Your address allows us to provide you with the best service possible: Select a specific service below to proceed: or choose from the popular services for change. The R wire is the most important, and it is the only one that will have power on it until your thermostat has turned on. You want to have a thorough understanding of the thermostat before you begin working. The 6th wire is the aux heat wire, and you should connect light blue to the X/Aux terminal. The most basic of systems (such as an older heat only forced air / gas furnace with a standing pilot light) only need two wires for control. An older thermostat had its cover removed. Thermostat cabling is color coded to easily identify which cable goes to which port on each board. If you just have an R wire, its responsible for powering your entire HVAC system (through the use of a transformer). Rc wires are for air conditioning systems or dual transformer systems. Since furnaces only use two wires for power and operation, smart controls cannot function properly without the extra wire. The white wire underneath your thermostat connects to your heating system. 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. Of course, you still need the red wire for power. If you have any questions or comments on your furnace situation, feel free to add a comment below. 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. Its used for systems that dont provide a C wire but have a thermostat that requires one. The heating is activated whenever you get R (power) to W. That will then activate the furnace or burner inside your HVAC system, which is essential for providing heat. White - The white wire is what connects to the (auxiliary) heat on your system. Step 4: Now connect all the wires to the new thermostat and check every option to ensure its working. When you need to wire a new thermostat or install a new thermostat from scratch, it can get confusing. The terminals are usually marked R and W. But the rest of the world isn't quite so helpful. You will have a white wire if your thermostat regulates your heating. You'll be wanting to cool down, then. The color of the wire varies from installer to installer, but it appears light blue is usually the go-to color for this terminal. The 5 wire system is essentially a 4 wire set up with the addition of the C-wire once again. The next step up from the older home systems was the introduction of the fan on / auto switch. 64 precision bits, iFixit's 4 mm aluminum screwdriver handle, and a flex extension. 2019 Mathison Air Conditioning, All rights reserved. 2 wire systems are used for every thermostat and HVAC component out there. Alternately, look for thermostats that state that a c-wire is unnecessary for operation. Central heating and air with dehumidifiers or vent fans, for example, or heat pumps using reversing valves and two-stage heating will use this wiring type. The E terminal is for emergency heating, which occurs when the system runs completely on the second stage heat source. I dont endorse many projects, but this is one that I fully endorse The Basics of Household Wiring DVD or e-book. Nest thermostats have become popular and claim to be able to work without a C wire. Terms, conditions and exclusions apply. It runs to the R, RH and RC terminals, depending on how the thermostat is used. One labeled HUM and the other DHUM, DHUM has a red wire connected to it. The green wire underneath your thermostat connects to the fan of your furnace or air handler. Dreo Space Heaters for Indoor Use, Portable Electric Heater for Bedroom Large Room Office Garage, 1500W Fast PTC Ceramic Heating with Remote, Thermostat, Oscillating, Timer, Multiple Safety Protection, De'Longhi DeLonghi TRD40615E Full Room Radiant Heater, 27.20 x 15.80 x 9.20, White. The thermostat wire comes in a range of gauges which can be determined based on the number of conductors needed to power your thermostat/device. DISCLAIMER: All wallpapers and backgrounds found here are believed to be in the "public domain". Prior to getting involved in this project, you should always read the thermostat manufacturers instructions. You will typically find 18/5, 18/6, or 18/8 on the label. Today's systems incorporate their own WiFi signals to be able to program the device from anywhere. Themes, February 13, 2018 /. Click here for more information. Once the faceplate is detached take a look at the wire configuration of your unit. Contact us today to schedule your inspection and see what we can do for you. C stands for common and it's usually labeled as C. It can be any color. This information should help you see how to connect it. The yellow wires terminate at your compressor contactor via an air handler. That control can be digital or analog, but it all ends up going through the thermostat wires. a high level for extremely hot or cold days, and a low level for mild days). If you are the rightful owner of any of the pictures/wallpapers posted here, and you do not want it to be displayed or if you require a suitable credit, then please contact us and we will immediately do whatever is needed either for the image to be removed or provide credit where it is due. AC Size GuideBTU to TonnageSEER to EEREER to SEEREER to COP, Watts to AmpsKilowatts to AmpsKilowatts to BTUKVA to AmpsACH Calculations, After a HVAC Quote - Call a Licensed Technician. Newer homes include them automatically in the build to be up to code. Heat Pump Thermostat Wiring Diagram. Theres a lot to keep track of when it comes to thermostat wires! You use this terminal for second stage heat. If youre replacing your thermostat for the first time, you might notice that the wires are connected to different terminals, each of which is denoted by a certain letter. Causes, Troubleshooting & Fixes. You will either need to run a new bundle, a single wire, or use an adapter kit. The common wire links to the C terminal. 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 thermostat, look for a wire that is attached to a terminal marked with the letter "C." You are now prepared for general installation if you have a c-wire. I have an old Lennox and its terminals are G, P C, H, V. I cant get it to work so It may have problems. Tape the wire bundle to the wall. In the most basic system, this functionality is provided by use of a fan center relay, and the low voltage wiring to the thermostat now will require a minimum of three wires (for heat only units) and four wires (for heat / cool / fan) for control. This means youll have more wires to connect when you change your thermostat. You may want to mark the terminal where each wire connected. | Powered by WordPress. For example, dehumidifiers require the use of the X or Aux line. Step 4. Were republishing it now as part of a home-focused week at iFixit, and because more people are searching for this kind of fix right now. 2.3K 249K views 4 years ago HVAC Wiring Diagrams & Schematics I Show The Low Voltage Thermostat Wiring Diagrams for Heat Pumps, Electric Strip Heating, Furnaces, Air Conditioners, Boilers,. Place the thermostat's plate against the wall where it will be installed. This wire is responsible for triggering the blower fan. Youll usually find two-stage heating in locations where people experience extremely cold winters. The most common size for wiring is 18 gauge because they typically come with 5 conductor wires which have become the standard for low voltage stats and HVAC devices. Verify that they adhere to the industry's standards outlined in Step 1. 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. Now that you are armed with a basic understanding of the temperature control system in your home, you should now be able to identify what kind of system you have, and what type of functions you will need if replacing or up-grading your existing thermostat. A new system may need as many as ten wires (like a two-stage heat, two-stage cooling system, heat pump reversing valves, fan control, etc.). You will need to remove the tape and wire bundle to slide the mount over them. When you need to wire a new thermostat or install a new thermostat from scratch, it can get confusing. The heat pump system setup differs from a standard unit. When you buy a new thermostat wiring bundle, it will come with a slashed number. L/A - A - Input for heat pump fault. With a little bit of knowledge, anyone can tackle this common DIY project with ease. When taking into consideration your thermostat wiring colors, the orange wire typically connects to the O terminal while the dark blue wire connects to the B terminal. If you have any doubts,getaprofessional thermostat installation. Each summer we help thousands of people find the best room air conditioners and heaters for their needs. It terminates in your outdoor condenser for reversing valve operation from hot to cold. When you purchase an item through links on our site, we may earn an affiliate commission. Red, white, yellow, and green go to their respective terminals (R/RC, W, Y, G). Mar 25, 2020 The green wire connects to terminal G on your thermostat. 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. RH stands for the power to the heating, and RC stands for Power to cooling. What are different thermostats used for? If youre not sure which wire represents what, try tracing the wire to the source to determine its purpose. Your Source for Local Home Service Experts.