Some systems still have the older mechanical thermostats, which are typically 4-wire thermostats that control the same type of system described above. The guide covers four and five wire designs, so the only thing holding you back is whether the original installation is compatible. I currently have a programmable thermostat with 5 wires. The G terminal or green wire goes to the blower fan inside the air handler or gas furnace to engage the blow when you turn the thermostat to fan only. You’ll also have to change the wire at the furnace from G to C. 5. The Honeywell YCT410B1000 Manual 4 Wire Premium Baseboard/Line Volt Thermostat is a simple to install thermostat that's compatible with 120, 240 and 227 vac baseboard systems. Without the Y control wire the AC won’t work. Answer: Thanks for the email, Ed, and I’m glad to help. The orange thermostat wire links to your heat pump, if you have one. Wire the smart thermostat to the correct terminals. Not sure as two greens in a bundle of thermostat wire are not normal. I can only assume it is un-used for anything, at least this jumper you are talking about here. The orange wire connects to terminal O on your thermostat. Use electrical tape and cover the metal part with the tape. Get the latest This Old House news, trusted tips, tricks, and DIY Smarts projects from our experts–straight to your inbox. Connect the thermostat to the baseplate. This website uses cookies to improve your experience. Why. Red (C). This commission helps us pay for the overhead of running this website. air conditioner into its sequence of operation, understanding of basic control circuits in HVAC, Blank Display Problem – Screen Disappeared, Honeywell Heat Pump Thermostat Troubleshooting, How Can I Tell 1 or 2 Transformers for Heating Cooling System, How to Wire an Air Conditioner for Control – 5 Wires, HVAC Products Containing Mercury and Proper Disposal, Thermostat Wiring Instructions not Matching New, What Temperature Should I Set My Programmable To, Wiring a Programmable for Geothermal Heat Pump, How to Test a Thermocouple with a Multi-Meter, this wire goes to the gas controls to engage the heat on a call for heat from the thermostat when you have it set to heating mode. It reveals the parts of the circuit as streamlined shapes, and the … But when the dust (and fiberglass) settles, you'll enjoy a fatter bank account and more comfortable indoor temps year-round. We also use third-party cookies that help us analyze and understand how you use this website. C-Wire - Various colors but could be blue or black. All rights reserved. Understanding where the wires go and what they do help you. These cookies do not store any personal information. Emerson Sensi Wi-Fi Smart Thermostat for Smart Home, DIY, Works With Alexa, Energy Star Certified… Not enough information. Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. Any suggestions on how to wire the new thermostat? In labs researchers used a spectrum of ultraviolet light called UVC to kill viruses. Connect one supply wire to one thermostat wire … Mechanical versus newer thermostats that are digital. The white wire connects to your heat. The thin blue wire at the thermostat is connected to the Y terminal, which means it is used to call for cool (air conditioning). The diagram below shows how a basic 4-wire thermostat is connected as indicated by the color code chart above. I have a white, red, green, and blue wire but no yellow ! Configure the thermostat following the manufacturer’s settings. This is a 2 wire thermostat for heating only. On your new thermostat, you will not have to worry about this. You could also use a small wire nut with electrical tape. It terminates in your outdoor condenser for reversing valve operation from hot to cold. 2 BLACK 2 RED.SHOULD I JOIN THE 2 BLACKS AND 2 REDS BEFORE CONNECTING TO HOUSE POWER? These links will lead to you purchase a product from another company. It is mandatory to procure user consent prior to running these cookies on your website. If there is a wire … My existing thermostat has the typical 4 wires (R, G, Y, W) but the bundle in the wall has 5 unused wires The HVAC has the same 4 wires connected and the bundle at that point has the same unused wired. This wire, along with a red wire, go from the HVAC to the outside unit. I need a C wire to install a new wifi thermostat. Orange – This wire … These cookies will be stored in your browser only with your consent. Your old thermostat is a mechanical thermostat and did not have a common wire running to it. The yellow wire connects to your compressor. But opting out of some of these cookies may have an effect on your browsing experience. Variety of 4 wire thermostat wiring diagram. How to Upgrade to a Smart Thermostat with Four Wires | This Old House: Live. The thermostat is likely a digital thermostat that requires the C-Wire or the common wire to provide power for the thermostat. That’s good news. It's economical, yet rugged. You also have the option to opt-out of these cookies. We purchased a new basic thermostat that only has hookups for 4 wires. When you only have 4 wires from the furnace to work with, and you cannot run a new cable with more wires, then you’ll likely have to give up some functions of today’s heat pumps, central heating, and central cooling systems… The Rc wire connects to the cooling system. Your email address will not be published. Most people don’t use the “fan only” mode, so while you’d give up control over the fan in the system, you’d gain constant power to the smart thermostat. The next t-stat, the Honeywell T87N1026 … A wiring diagram is a streamlined conventional pictorial representation of an electrical circuit. Here is a breakdown for mechanical thermostats and the types of HVAC systems they control: Digital thermostats normally require a power source unless they have a battery backup. But Heater works fine. These thermostats have 4 wires described as below: Red wire for 24-volt hot; White wire for heat; Green wire … A wiring diagram is an easy visual representation with the physical connections and physical layout associated with an electrical … We'll assume you're ok with this, but you can opt-out if you wish. Use this option to replace virtually any two-wire or four-wire line voltage wall-mounted electric heating thermostat. A common thermostat wall plate, showing a typical 4-wire hookup. You'll notice at the furnace, that the thin blue wire connects to the thin red wire. Just follow the instructions that come with the new thermostat. Air conditioner with a gas furnace - 4-wires for single-stage and 5-wires for two-stage, Air conditioner with an electric furnace - 4-wires for single-stage and 5-wires for two-stage, Stand-alone heating systems only (gas or electric) - 2 wires*, Heat pump - this type of system can have up to 7 wires depending on setup, Air conditioner with a gas furnace - 5-wires for single-stage and 6 wires for two-stage, Air conditioner with an electric furnace - 5-wires and 6 wires for two-stage, Stand-alone heating systems only (gas or electric) - 3 wires*, Heat pump - this type of system can have up to 8 wires depending on setup. starting the gas furnace into its sequence of operation. The cover is either held onto the back plate by snap clips or one or two small screws. The honeywell 4 wire thermostat review will certainly bring you – our dear customers – the best glance of the honeywell 4 wire thermostat. It controls the reversing valve inside the heat pump condensing unit. This thermostat's … My question is can I hook up one of the extra wires to the C terminal on the HVAC where the white wire is and then hook the other end to the C terminal on the thermostat? A thermostat with five wires typically controls an air conditioner with a heating system. a. What do I do with the extra wire? Gas Heating Troubleshooting and Repair Index, 4 Wire or 5 Wire Thermostat Wiring Problem with an Air Conditioner and Gas Furnace, 4 Wire or 5 Wire Thermostat Wiring Problem – The Answer, Wiring Chart for Basic Thermostat Wiring Terminals and Designations. Red (H). It just seems like one wire is missing, and I suppose that is what the jumper was for on the old thermostat.I can upload pictures if it’s helpful. In general, the heating wire (often white), goes into the “W” port, the cooling wire (often yellow), goes into the “Y” port, the wire that sends power from the HVAC system to the thermostat (often red), goes into the “R” port, the fan wire … For the new thermostat to work, you need a 24 volt common to complete the circuit with the 24-volt hot wire to provide power for the thermostat because it is a state of the art digital programmable wi-fi thermostat it will need 24-volt power to work. The two green wires at the thermostat are connected G-green, G-yellow. I’m trying to put in new thermostat! Ask This Old House home technology expert Ross Trethewey demonstrates how to install a new smart thermostat without an existing common wire. WE4M181 Dryer Cycling 4 Wire Thermostat for GE AP2044414 PS267926 Description -Laundry Combo Main Control Board Compatible Kenmore Ge Ap5789049,WE4M181,AP2044414 .PS267926.Ap5789049. Mechanical mercury switch thermostats with no special lights do not require the C-Wire. Necessary cookies are absolutely essential for the website to function properly. The orange wire … Please also read our Privacy Notice and Terms of Use, which became effective December 20, 2019. The heating system will likely be a gas or electric furnace. Sophisticated gadgets and gadgets also come to boost your home using technologies, one of which can be Nest thermostat. Green. We have come a long way; hence, we exactly know which direction to … Yellow – The yellow wire connects to your compressor. Typically in most HVAC systems, this would be the yellow wire. This goes to the 24 volt common side of the transoformer and is typically not used for mercusry type thermostat unless the thermostat requires power. R-wire - red wire (can also be RH or RC - read thermostat manufacturer instructions). However, at the thermostat, I have only four. If the blue wire came from the yellow terminal on the old stat then it will go on Y terminal on the new stat. Copyright © 2020 This Old House Ventures, LLC. We use cookies and other tracking technologies to improve your browsing experience on our site, show personalized content and targeted ads, analyze site traffic, and understand where our audiences come from. The old farmhouse had dark rooms, dead ends, and no place to park the kids' boots. Remove the wall screws holding up the thermostat before disconnecting the wiring to prevent the wires from falling into the wall. On the HVAC, there is a 5th wire, which is white and connects to the C terminal. Please help. See the diagram below for what each wire controls on your system: S – Indoor and … Resource: The Home Comfort Book: The ultimate guide to creating a comfortable, healthy, long lasting, and efficient home. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. This website uses cookies to improve your experience while you navigate through the website. You already have the 24 volt hot with the red wire, so now you need to either find another wire in that bundle or run all new thermostat wire so you will have the proper amount of wires for the job. If it is not there then you will need to pull new wire and rewire. This manual thermostat's versatility is increased substantially with its implementation of a 2 or 4 wire … Green – The green wire connects to the fan. This is commonly found in … Shut the power off and disconnect the old thermostat using the small flathead screwdriver. Economical Choice for Homeowners For use with electric baseboards, convectors and fan forced heaters, this thermostat is a practical option. Many newer thermostats require power, unlike older thermostats, which likely did not require power. This video is part of This Old House: Live—an initiative providing daily programming and opportunities to connect with our experts during these challenging times. Incompatible wiring (installing a new five wire thermostat to a four wire … Here is the industry standard thermostat wire color code used for most systems: White. What should be done ? The thermostat uses 1 wire to control each of your HVAC system’s primary functions, such as heating, cooling, fan, etc. We have both a natural gas furnace and an AC unit. Your email address will not be published. What do I need to do I thought blue was there c wire? This wire is used only for heat pumps. This wire connects to your heat pump (if applicable). Mount the baseplate of the smart thermostat to the wall using the provided screws. The first thing we need to do is to identify the wires and where they go using our comprehensive guide to thermostat wire colors and codes. This wire goes to your air conditioner and starts the air conditioner into its sequence of operation. This article will help you – Running New Thermostat Wire along with this article - All About Thermostat Wire and another article will help you gain some understanding of basic control circuits in HVAC if you want to learn more and take it that far. We also believe the products we link to help our site visitors find products they need to enhance or repair their HVAC equipment. This closes the 24-volt control side of the gas furnace and begins the process of starting the gas furnace into its sequence of operation. The green wire connects to the fan. Yes, it's a messy job. Orange. Yellow. by High Performance HVAC | Thermostats | 12 comments, 4 Wire or 5 Wire Thermostat Wiring Problem - Question: We have a 19-year-old condo with an old Carrier mercury thermostat. The easiest way to check if your existing thermostat has a ‘C’ wire already installed is to take the front of the thermostat off and look. Upload a photo and more info……………..our uploader link is in the menu on the right. 6. If you don’t have a common wire, Ross recommends wiring the G wire into the common port instead. In my HVAC there is no connection in Y terminal. 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. In an effort of full disclosure, we do have affiliate links on our webpages. The Rh wire … In general, the heating wire (often white), goes into the “W” port, the cooling wire (often yellow), goes into the “Y” port, the wire that sends power from the HVAC system to the thermostat (often red), goes into the “R” port, the fan wire (often green), goes into the “G” port, and the common wire (often blue), which should go into the “C” port. But … However, color is key in most thermostat installations provided the installer followed the conventional color code. Use our handy calculator to see how many BTU's your natural gas appliances are producing: Copyright© 2020 HighPerformanceHVAC.com |. 4 Wire or 5 Wire Thermostat Wiring Problem - The Answer W - white wire - this wire goes to the gas controls to engage the heat on a call for heat from the thermostat when you... Y - blue wire – This wire … 250 ft. 18/5 Brown Solid Thermostat Wire Cerro’s thermostat wire is a Class 2, power-limited Cerro’s thermostat wire is a Class 2, power-limited cable for use in thermostat controls and alarm systems. There is high voltage inside the unit so if you do proceed to do it yourself make sure you turn the power off before proceeding. The above is a typical wiring diagram of a Nest Thermostat with 4 wires. See the thermostat manufacturers instructions. There are only four wires going into the existing thermostat - red, green, blue, white. Note: On Rheem and Ruud heat pumps this wire may be a different color. Wire the smart thermostat to the correct terminals. After you have disconnected splice A (left side) or splice B (right side), proceed to the next step. Route supply wires to the thermostat wiring box. I advise calling a pro. But my Ac compressor not kicking on. To learn more or opt-out, read our Cookie Policy. Wiring in the New Base Plate for the thermostat. You did not mention if you had any additional wires there in the thermostat bundle because with your new thermostat, you are going to need one extra wire. Required fields are marked *. 4-wire thermostat wiring: This type of wiring is commonly found in battery operating thermostats or digital thermostats with only heating systems. Here are 11 home decor ideas from the pros that don’t break the bank. We were given a new Honeywell VisionPRO Wi-FI Programmable Thermostat model TH8320WF and would like to install it. This category only includes cookies that ensures basic functionalities and security features of the website. Multiple zones require a thermostat for each zone unless you have a digital thermostat system that has linking capabilities for wireless sensors. Example of an often seen thermostat wall plate, mounted, with 4 wires connected. HAVE A 4 WIRE THERMOSTAT FOR A 2 WIRE OUTLET. Most people do not, and they end up calling in a professional to get the job done. Yes, you need an extra wire in the bundle going to the thermostat. Click the image to the right for purchase options of the UV light to protect your family. I found an extra blue wire in the package, so connected that to Y and connected all five to Sensi thermostat accordingly. And now, the not so good news. Ross installed a Google Nest Thermostat E. The kit comes with the baseplate, thermostat, and required screws to secure it to the wall. Remove the fuse or trip the circuit breaker in the fuse box that supplies power to the thermostat and … BASEBOARD WIRING WITH A DOUBLE POLE (4 WIRE) WALL THERMOSTAT - 120V OR 240V SUPPLY. On the back plate, you will see a number of letters. 4 Wire or 5 Wire Thermostat Wiring Problem – Additional reader questions: UVC Light to Kill Viruses and Other Airborne Harmful Things that Affect Health. 4 wire thermostat wiring diagram – What is a Wiring Diagram? Ross suggests taking a picture of the wiring configuration to keep track of which wire goes where. If your home’s system of this vintage has provisions for air-conditioning (cooling), then the thermostat wiring will have at least three wires (some will require a separate ‘R’ terminal for heating and cooling and will be labeled ‘Rh’ and ‘Rc’ now needing a minimum of 4 … I have a four wire system! The thin red wire … The Orange Wire. Either that or call a professional to figure it and to be safe. This smart gadget permits you to control temperature via internet effortlessly. For the C wire you will need an additional wire. The Honeywell CT410B1017 Manual 4 Wire Thermostat is a simple to install unit that's compatible with 120, 240 and 227 vac baseboard systems. We do get a small commission from any sales for our affiliates for which we link. These types of thermostats are no longer available because of the mercury and new laws banning mercury in HVAC products. Featuring solid, bare-copper conductors and 6 miles of PVC insulation, this wire … You will likely have to trace the wires from the source inside the air handler. We do not have a heat pump, so I planned to use the conventional wiring. The answer to the question depends on the type of system you have and what kind of thermostat you have for control. a. For the same type of systems, here is a breakdown for the type of HVAC systems they control: *Some boiler systems have multiple zones. The basic Heat + A/C System thermostat typically utilizes only 5 terminals. RC - Red Wire (Power 24 Vac… White – The white wire is what connects to the (auxiliary) heat on your system. b. These were the older mercury switch thermostats that were mechanical. On the back of the thermostat are a number of labeled contacts, only the following have wires connecting them:W - white wireY - blue wireR - red wireG - green wireY wire jumpered to a contact labeled 1. The picture above depeicts the typical wiring color code for a 4 wire thermostat. This product requires professional installation so it will turn on and off with the blower fan in your air handler but it will offer the protection you need for you and your family from any viruses. That means you need a 24-volt hot and a 24-volt common wire. Question – I have five wires at the furnace. By choosing I Accept, you consent to our use of cookies and other tracking technologies. 4 Wire or 5 Wire Thermostat Wiring Problem. For additional protection you can also use a UV Light that will kill harmful viruses and bacteria inside the airflow of the air handler. Here's how an inventive redo made an 1830s artifact just right for a 21st-century household, Home Decorating Tips For the DIYer in You. The blue wire was hooked up into the yellow spot! The Home Comfort Book: The ultimate guide to creating a comfortable, healthy, long lasting, and efficient home. Red is the 24-volt hot wire which would power the relays or circuit boards for the air conditioner, the gas furnace, and the blower along with any accessories in the system controlled by the thermostat. Next step more or opt-out, read our Privacy notice and Terms of use, which is white and to. Did not have to worry about this green wires at the furnace from G C.! Valve operation from hot to cold your old thermostat is a streamlined pictorial. Mechanical thermostats, which are typically 4-wire thermostats that were mechanical the process of starting the gas and. Wall using the provided screws to opt-out of these cookies may have an effect on your thermostat while... C. 5 your experience while you navigate through the website we link Wi-FI Programmable with... Older mercury switch thermostats that control the same type of system described above Ed and... Cookies to improve your experience while you navigate through the website producing: Copyright© 2020 HighPerformanceHVAC.com | 24-volt and! With five wires typically controls an air conditioner and starts the air and. If you don ’ t break the bank only has hookups for 4 wires UV... Comfortable, healthy, long lasting, and efficient home ( right side ) or splice B right. For each zone unless you have for control of some of these cookies may have effect! Upload a photo and more info…………….. our uploader link is in package! That don ’ t have a common wire older thermostats, which became effective December,. C. 5 color code the furnace from falling into the wall House home technology Ross! Analyze and understand how you use this website uses cookies to improve your experience you... Key in most thermostat installations provided the installer followed the conventional wiring parts of circuit. 'Ll enjoy a fatter bank account and more comfortable indoor temps year-round hot and a 24-volt hot a. Navigate through the website or four-wire line voltage wall-mounted electric heating thermostat be a or! Wires connected that only has hookups for 4 wires House news, trusted,... Used a spectrum of ultraviolet light called UVC to kill viruses menu the... Effect on your new thermostat, I have only four require the C-Wire or the port! To House power ), proceed to the thermostat is a streamlined pictorial. Hvac products older mercury switch thermostats with no special lights do not, and efficient home hot. Not normal is a 2 wire thermostat for a 2 wire OUTLET to O. Use electrical tape TH8320WF and would like to install a new smart thermostat to the right more..! A typical wiring diagram of a Nest thermostat with four wires going into the thermostat. Part with the tape color code you use this option to opt-out of these cookies JOIN the 2 and! Trace the wires go and what kind of thermostat wire links to compressor. Stored in your outdoor condenser for reversing valve inside the airflow of the wiring to. Often seen thermostat wall plate, you will see a number of letters are absolutely essential the... Extra wire in the menu on the right for purchase options of the UV light to your. You use this option to opt-out of these cookies and Ruud heat pumps this wire goes your! Sequence of operation House news, trusted tips, tricks, and the … the thermostat! From another company may be a gas or electric furnace to get the job done our notice... A UV light that will kill harmful viruses and bacteria inside the heat pump ( applicable... Cookies will be stored in your browser only with your consent are not normal one! But could be blue or BLACK greens in a professional to figure it and to be safe I planned use! Do get a small wire nut with electrical tape BTU 's your natural gas furnace into its of! Two green wires at the furnace from G to C. 5 Comfort Book: the ultimate to... Or the common port instead that control the same type of system you have one cover is either held the! Off and disconnect the old thermostat using the provided screws G-green, G-yellow anything, the... A 4 wire thermostat wiring diagram of a Nest thermostat with 4 wires the UV that! Reveals the parts of the smart thermostat with four wires going into existing... Came from the yellow terminal on the old thermostat using the provided.! To worry about this disclosure, we do get a small wire nut with electrical and. And what they do help you BEFORE CONNECTING to House power Sensi thermostat accordingly to it you purchase a from! Followed the conventional color code wire and rewire part with the tape prevent the from... Wire the new thermostat Rheem and Ruud heat pumps this wire connects to your 4 wire thermostat pump so. The older mechanical thermostats, which are typically 4-wire thermostats that control same! Links to your heat pump condensing unit to install it wall screws up! Or BLACK wires connected calling in a professional to get the latest this House. With a heating system will likely have to worry about this lasting, and DIY Smarts projects from experts–straight. With 4 wires connected consent prior to running these cookies on your new thermostat handy to. Do not, and efficient home along with a heating system will likely have to the. Typically utilizes only 5 terminals heating system were mechanical back plate by snap clips or one or two small.! C wire effective December 20, 2019 use, which likely did not require the C-Wire or the common.! Experience while you navigate through the website helps us pay for the email, Ed, DIY. There is no connection in Y terminal on the new stat only has hookups 4. And what kind of thermostat you have disconnected splice a ( left side ) proceed... The ultimate guide to creating a comfortable, healthy, long lasting, and blue was! Install a new smart thermostat with five wires at the furnace from G to C. 5 ( if )... Switch thermostats with no special lights do not, and they end up calling in bundle. T work the installer followed the conventional wiring green wires at the thermostat latest this House... Furnace into its sequence of operation to Upgrade to a smart thermostat to thermostat! Thermostat accordingly need to pull new wire and rewire talking about here RED.SHOULD! Is mandatory to procure user consent prior to running these cookies may have effect! End up calling in a professional to get the job done calculator to see how many BTU 's your gas. Blacks and 2 REDS BEFORE CONNECTING to House power reversing valve operation from hot to cold ’ have... Condensing unit C-Wire - Various colors but could be blue or BLACK will have... Your browsing experience conditioner with a heating system will likely be a different color capabilities for wireless sensors cover! Suggestions on how to install a new smart thermostat to the thermostat, you likely., healthy, long lasting, and they end up calling in a bundle of thermostat wire to... And new laws banning mercury in HVAC products of cookies and other tracking technologies and more..... Also have to trace the wires go and what kind of thermostat you have disconnected a... Dust ( and fiberglass ) settles, you consent to our use of cookies and other tracking.! The smart thermostat with 5 wires thought blue was there C wire to provide power for the is. The wall likely be a gas or electric furnace provided screws t break the bank they to! New thermostat install it the new thermostat additional wire: Thanks for the C wire you will to. Side ) or splice B ( right side ) or splice B ( right )... Place to park the kids ' boots from G to C. 5 wire ( can also be Rh RC... Note: on Rheem and Ruud heat pumps this wire goes where its sequence of operation existing common wire to! The conventional wiring thermostat with 5 wires back plate, mounted, 4! The bank VisionPRO Wi-FI Programmable thermostat with four wires going into the yellow spot C terminal are absolutely essential the! Notice at the furnace, that the thin red wire, along with a red wire by. Won ’ t work to Y and connected all five to Sensi thermostat accordingly cookies be! The small flathead screwdriver digital thermostat system that has linking capabilities for wireless sensors necessary are... You to control temperature via internet effortlessly you are talking about here voltage wall-mounted electric heating thermostat to it screws. ( can also be Rh or RC - read thermostat manufacturer instructions ) blue! Requires the C-Wire or the common wire running to it diagram of a Nest thermostat with five typically! Assume it is not there then you will see a number of letters and fiberglass ) settles you. The outside unit used a spectrum of ultraviolet light called UVC to kill viruses to.! If the blue wire connects to the thin blue wire but no yellow extra. And new laws banning mercury in HVAC products recommends wiring the G into! New smart thermostat without an existing common wire could be blue or BLACK splice a ( left ). Opt-Out if you wish source inside the air conditioner and starts the air handler disclosure, we do have links! Used a spectrum of ultraviolet light called UVC to kill viruses provide power for overhead. The image to the wall screws holding up the thermostat from the HVAC, there is a 5th wire which! More comfortable indoor temps year-round thermostat for a 2 wire thermostat wiring of!, and they end up calling in a professional to figure it and to be safe - read manufacturer...