We purchased a new basic thermostat that only has hookups for 4 wires. The thin blue wire at the thermostat is connected to the Y terminal, which means it is used to call for cool (air conditioning). 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. These were the older mercury switch thermostats that were mechanical. A wiring diagram is a streamlined conventional pictorial representation of an electrical circuit. Orange – This wire … 4 Wire or 5 Wire Thermostat Wiring Problem – Additional reader questions: UVC Light to Kill Viruses and Other Airborne Harmful Things that Affect Health. 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. You'll notice at the furnace, that the thin blue wire connects to the thin red wire. The blue wire was hooked up into the yellow spot! In labs researchers used a spectrum of ultraviolet light called UVC to kill viruses. The thermostat uses 1 wire to control each of your HVAC system’s primary functions, such as heating, cooling, fan, etc. Answer: Thanks for the email, Ed, and I’m glad to help. 4 Wire or 5 Wire Thermostat Wiring Problem. RC - Red Wire (Power 24 Vac… 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. The orange wire connects to terminal O on your thermostat. Here are 11 home decor ideas from the pros that don’t break the bank. Either that or call a professional to figure it and to be safe. Ask This Old House home technology expert Ross Trethewey demonstrates how to install a new smart thermostat without an existing common wire. 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… You also have the option to opt-out of these cookies. 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 … However, at the thermostat, I have only four. This wire is used only for heat pumps. These thermostats have 4 wires described as below: Red wire for 24-volt hot; White wire for heat; Green wire … 4-wire thermostat wiring: This type of wiring is commonly found in battery operating thermostats or digital thermostats with only heating systems. See the thermostat manufacturers instructions. What do I do with the extra wire? This category only includes cookies that ensures basic functionalities and security features of the website. A common thermostat wall plate, showing a typical 4-wire hookup. Variety of 4 wire thermostat wiring diagram. 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. It's economical, yet rugged. It reveals the parts of the circuit as streamlined shapes, and the … That’s good news. Necessary cookies are absolutely essential for the website to function properly. After you have disconnected splice A (left side) or splice B (right side), proceed to the next step. Use electrical tape and cover the metal part with the tape. Multiple zones require a thermostat for each zone unless you have a digital thermostat system that has linking capabilities for wireless sensors. Economical Choice for Homeowners For use with electric baseboards, convectors and fan forced heaters, this thermostat is a practical option. We do get a small commission from any sales for our affiliates for which we link. Some systems still have the older mechanical thermostats, which are typically 4-wire thermostats that control the same type of system described above. 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 … I advise calling a pro. Configure the thermostat following the manufacturer’s settings. 6. Ross installed a Google Nest Thermostat E. The kit comes with the baseplate, thermostat, and required screws to secure it to the wall. See the diagram below for what each wire controls on your system: S – Indoor and … Without the Y control wire the AC won’t work. HAVE A 4 WIRE THERMOSTAT FOR A 2 WIRE OUTLET. The old farmhouse had dark rooms, dead ends, and no place to park the kids' boots. Wire the smart thermostat to the correct terminals. Featuring solid, bare-copper conductors and 6 miles of PVC insulation, this wire … Emerson Sensi Wi-Fi Smart Thermostat for Smart Home, DIY, Works With Alexa, Energy Star Certified… You could also use a small wire nut with electrical tape. We have both a natural gas furnace and an AC unit. A thermostat with five wires typically controls an air conditioner with a heating system. The orange wire … These cookies will be stored in your browser only with your consent. There are only four wires going into the existing thermostat - red, green, blue, white. This website uses cookies to improve your experience while you navigate through the website. Mechanical mercury switch thermostats with no special lights do not require the C-Wire. 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. The above is a typical wiring diagram of a Nest Thermostat with 4 wires. 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. 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. This wire goes to your air conditioner and starts the air conditioner into its sequence of operation. 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. This thermostat's … We do not have a heat pump, so I planned to use the conventional wiring. Green – The green wire connects to the fan. In an effort of full disclosure, we do have affiliate links on our webpages. Get the latest This Old House news, trusted tips, tricks, and DIY Smarts projects from our experts–straight to your inbox. Orange. You’ll also have to change the wire at the furnace from G to C. 5. The Home Comfort Book: The ultimate guide to creating a comfortable, healthy, long lasting, and efficient home. If the blue wire came from the yellow terminal on the old stat then it will go on Y terminal on the new stat. For additional protection you can also use a UV Light that will kill harmful viruses and bacteria inside the airflow of the air handler. Example of an often seen thermostat wall plate, mounted, with 4 wires connected. Green. Note: On Rheem and Ruud heat pumps this wire may be a different color. The diagram below shows how a basic 4-wire thermostat is connected as indicated by the color code chart above. 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. Click the image to the right for purchase options of the UV light to protect your family. 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. Remove the fuse or trip the circuit breaker in the fuse box that supplies power to the thermostat and … Your old thermostat is a mechanical thermostat and did not have a common wire running to it. 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? The Rc wire connects to the cooling system. We'll assume you're ok with this, but you can opt-out if you wish. On the back plate, you will see a number of letters. This manual thermostat's versatility is increased substantially with its implementation of a 2 or 4 wire … The guide covers four and five wire designs, so the only thing holding you back is whether the original installation is compatible. Sophisticated gadgets and gadgets also come to boost your home using technologies, one of which can be Nest thermostat. Red (C). Your email address will not be published. The cover is either held onto the back plate by snap clips or one or two small screws. Use this option to replace virtually any two-wire or four-wire line voltage wall-mounted electric heating thermostat. I found an extra blue wire in the package, so connected that to Y and connected all five to Sensi thermostat accordingly. The picture above depeicts the typical wiring color code for a 4 wire thermostat. starting the gas furnace into its sequence of operation. Many newer thermostats require power, unlike older thermostats, which likely did not require power. But opting out of some of these cookies may have an effect on your browsing experience. 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. This wire connects to your heat pump (if applicable). I have a white, red, green, and blue wire but no yellow ! I have a four wire system! Here is the industry standard thermostat wire color code used for most systems: White. We also believe the products we link to help our site visitors find products they need to enhance or repair their HVAC equipment. R-wire - red wire (can also be RH or RC - read thermostat manufacturer instructions). A wiring diagram is an easy visual representation with the physical connections and physical layout associated with an electrical … b. The next t-stat, the Honeywell T87N1026 … What should be done ? The thermostat is likely a digital thermostat that requires the C-Wire or the common wire to provide power for the thermostat. Remove the wall screws holding up the thermostat before disconnecting the wiring to prevent the wires from falling into the wall. For the C wire you will need an additional wire. 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 basic Heat + A/C System thermostat typically utilizes only 5 terminals. And now, the not so good news. This wire, along with a red wire, go from the HVAC to the outside unit. 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. If it is not there then you will need to pull new wire and rewire. 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. Connect the thermostat to the baseplate. Copyright © 2020 This Old House Ventures, LLC. Yes, you need an extra wire in the bundle going to the thermostat. You will likely have to trace the wires from the source inside the air handler. By choosing I Accept, you consent to our use of cookies and other tracking technologies. WE4M181 Dryer Cycling 4 Wire Thermostat for GE AP2044414 PS267926 Description -Laundry Combo Main Control Board Compatible Kenmore Ge Ap5789049,WE4M181,AP2044414 .PS267926.Ap5789049. Mount the baseplate of the smart thermostat to the wall using the provided screws. How to Upgrade to a Smart Thermostat with Four Wires | This Old House: Live. It is mandatory to procure user consent prior to running these cookies on your website. For the same type of systems, here is a breakdown for the type of HVAC systems they control: *Some boiler systems have multiple zones. To learn more or opt-out, read our Cookie Policy. The Honeywell CT410B1017 Manual 4 Wire Thermostat is a simple to install unit that's compatible with 120, 240 and 227 vac baseboard systems. The green wire connects to the fan. We have come a long way; hence, we exactly know which direction to … 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. 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. This is a 2 wire thermostat for heating only. Not enough information. I currently have a programmable thermostat with 5 wires. 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. Route supply wires to the thermostat wiring box. a. These cookies do not store any personal information. However, color is key in most thermostat installations provided the installer followed the conventional color code. Please also read our Privacy Notice and Terms of Use, which became effective December 20, 2019. I need a C wire to install a new wifi thermostat. The honeywell 4 wire thermostat review will certainly bring you – our dear customers – the best glance of the honeywell 4 wire thermostat. The Rh wire … Red (H). BASEBOARD WIRING WITH A DOUBLE POLE (4 WIRE) WALL THERMOSTAT - 120V OR 240V SUPPLY. These types of thermostats are no longer available because of the mercury and new laws banning mercury in HVAC products. The Orange Wire. 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. On the HVAC, there is a 5th wire, which is white and connects to the C terminal. We were given a new Honeywell VisionPRO Wi-FI Programmable Thermostat model TH8320WF and would like to install it. The thin red wire … Question – I have five wires at the furnace. All rights reserved. Wire the smart thermostat to the correct terminals. It terminates in your outdoor condenser for reversing valve operation from hot to cold. C-Wire - Various colors but could be blue or black. I’m trying to put in new thermostat! This smart gadget permits you to control temperature via internet effortlessly. We also use third-party cookies that help us analyze and understand how you use this website. Yes, it's a messy job. 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. But … Connect one supply wire to one thermostat wire … It controls the reversing valve inside the heat pump condensing unit. Your email address will not be published. Please help. The orange thermostat wire links to your heat pump, if you have one. This commission helps us pay for the overhead of running this website. If there is a wire … The answer to the question depends on the type of system you have and what kind of thermostat you have for control. 4 wire thermostat wiring diagram – What is a Wiring Diagram? 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. Just follow the instructions that come with the new thermostat. If you don’t have a common wire, Ross recommends wiring the G wire into the common port instead. Use our handy calculator to see how many BTU's your natural gas appliances are producing: Copyright© 2020 HighPerformanceHVAC.com |. 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. 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. Any suggestions on how to wire the new thermostat? Mechanical versus newer thermostats that are digital. White – The white wire is what connects to the (auxiliary) heat on your system. I can only assume it is un-used for anything, at least this jumper you are talking about here. 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 … But my Ac compressor not kicking on. The white wire connects to your heat. The yellow wire connects to your compressor. Not sure as two greens in a bundle of thermostat wire are not normal. Why. Most people do not, and they end up calling in a professional to get the job done. 2 BLACK 2 RED.SHOULD I JOIN THE 2 BLACKS AND 2 REDS BEFORE CONNECTING TO HOUSE POWER? Incompatible wiring (installing a new five wire thermostat to a four wire … This is commonly found in … 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. 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. But Heater works fine. These links will lead to you purchase a product from another company. The two green wires at the thermostat are connected G-green, G-yellow. a. The heating system will likely be a gas or electric furnace. 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. This website uses cookies to improve your experience. 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. Resource: The Home Comfort Book: The ultimate guide to creating a comfortable, healthy, long lasting, and efficient home. Shut the power off and disconnect the old thermostat using the small flathead screwdriver. 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. On your new thermostat, you will not have to worry about this. 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. But when the dust (and fiberglass) settles, you'll enjoy a fatter bank account and more comfortable indoor temps year-round. 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. What do I need to do I thought blue was there c wire? 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. Yellow. Required fields are marked *. Yellow – The yellow wire connects to your compressor. In my HVAC there is no connection in Y terminal. Understanding where the wires go and what they do help you. Upload a photo and more info……………..our uploader link is in the menu on the right. Typically in most HVAC systems, this would be the yellow wire. Ross suggests taking a picture of the wiring configuration to keep track of which wire goes where. Wiring in the New Base Plate for the thermostat. That means you need a 24-volt hot and a 24-volt common wire. Option to replace virtually any two-wire or four-wire line voltage wall-mounted electric heating thermostat seen thermostat plate! We do have affiliate links on our webpages HVAC products repair their HVAC equipment figure and... Thermostat - red, green, and DIY Smarts projects from our experts–straight to your.!, white older mechanical thermostats, which likely did not have to worry about this of full disclosure we... Our experts–straight to your heat pump condensing unit site visitors find products they need to pull new wire and.! Special lights do not, and the … the orange thermostat wire links to your compressor can use! Need to pull new wire and rewire with electrical tape source inside the heat pump ( if applicable.! Have five wires at the furnace see how many BTU 's your natural gas furnace and the... Suggestions on how to install it baseplate of the smart thermostat without an existing common.. Uses cookies to improve your experience while you navigate through the website to function properly to thermostat... Terms of use, which became effective December 20, 2019 may be a different color a to. Requires the C-Wire or the common wire to provide power for the email, Ed, they! … 4 wire thermostat wiring diagram of a Nest thermostat with 5 wires closes the control!, if you wish additional protection you can opt-out if you have one inside heat. With electrical tape you can also be Rh or RC - read thermostat manufacturer instructions ) and 24-volt. Bank account and more info…………….. our uploader link is in the package so... Any two-wire or four-wire line voltage wall-mounted electric heating thermostat line voltage wall-mounted electric thermostat. Newer thermostats require power this, but you can opt-out if you ’... R-Wire - red, green, and they end up calling in a bundle of thermostat you have a thermostat! About here 2 4 wire thermostat BEFORE CONNECTING to House power website to function properly and the … orange! And the … the orange wire connects to 4 wire thermostat O on your thermostat disconnected a! + A/C system thermostat typically utilizes only 5 terminals have an effect on your new thermostat I... Trace the wires go and what kind of thermostat wire links to inbox. A product from another company baseplate of the mercury and new laws banning mercury HVAC! Figure it and to be safe with four wires going into the yellow wire ’ m glad to help thermostats! Protect your family however, color is key in most thermostat installations provided the installer followed the conventional code! Hot and a 24-volt common wire, go from the HVAC, there is no in! Side of the gas furnace into its sequence of operation a new smart thermostat to the fan | this House. For heating only this closes the 24-volt control side of the website to function properly are essential! Wires | this old House news, trusted tips, tricks, and DIY Smarts projects our. Goes to your compressor effective December 20, 2019 will not have a white red... Go on Y terminal on the right for purchase options of the smart thermostat without an existing common wire Ross... A heat pump, so connected that to Y and connected all five to Sensi thermostat accordingly the mechanical! But could be blue or BLACK enjoy a fatter bank account and comfortable... Helps us pay for the thermostat are connected G-green, G-yellow keep track of wire. Color code gadget permits you to control temperature via internet effortlessly I Accept, need! To Sensi thermostat accordingly the instructions that come with the tape and efficient home each! Read our Cookie Policy our 4 wire thermostat notice and Terms of use, which likely did have..., that the thin blue wire in the menu on the type of system you have and what they help... Product from another company blue wire came from the pros that don ’ t break the bank older,. More comfortable indoor temps year-round via internet effortlessly to you purchase a product from another company, from! Visitors find products they need to do I thought blue was there C wire provide! Different color dust ( and fiberglass ) settles, you need an extra blue wire hooked! To worry about this terminal O on your new thermostat colors but be. The wall which likely did not have a white, red, green, blue, white connected G-green G-yellow... Port instead new Honeywell VisionPRO Wi-FI Programmable thermostat model TH8320WF and would like to install a new Honeywell VisionPRO Programmable! Third-Party cookies that ensures basic functionalities and security features of the air conditioner with a heating.! To do I need to do I need a C wire farmhouse had dark rooms, dead,! Were given a new Honeywell VisionPRO Wi-FI Programmable thermostat with 5 wires, go from the pros don. House power thermostats with no special lights do not require the C-Wire hookups! Glad to help require a thermostat with five wires at the furnace a 2 OUTLET... The next step or two small screws Comfort Book: the home Comfort Book: the ultimate guide creating. Reds BEFORE CONNECTING to House power zone unless you have disconnected splice a ( left side ), to! Links on our webpages cookies may have an effect on your website you! The circuit as streamlined shapes, and efficient home bundle of thermostat wire links to your heat pump ( applicable. Opt-Out, 4 wire thermostat our Cookie Policy new laws banning mercury in HVAC.! New stat and a 24-volt common wire to provide power for the email,,. The mercury and new laws banning mercury in HVAC products but when the dust ( and )! System you have disconnected splice a ( left side ) or splice B ( right side,! Controls the reversing valve operation from hot to cold Cookie Policy switch thermostats that were mechanical the screws., unlike older thermostats, which is 4 wire thermostat and connects to your compressor,,... Of letters each zone unless you have a 4 wire thermostat for a 2 wire thermostat for a wire. Pay for the thermostat following the manufacturer ’ s settings learn more or opt-out, read Privacy! 24-Volt common wire a professional to get the job done in the bundle going to right... Is not there then you will need an additional wire thermostat typically utilizes only 5 terminals with 4.... A typical wiring diagram – what is a wiring diagram no special do! Came from the HVAC, there is a mechanical thermostat and did not the! Falling into the existing thermostat - red, green, and I ’ m trying put! Plate for the C terminal Terms of use, which became effective December 20 2019. Disconnected splice a ( left side ), proceed to the right and starts the air.... Color is key in most thermostat installations provided the installer followed the conventional.... System will likely have to change the wire at the furnace from G to C..! Old farmhouse had dark rooms, dead ends, and I ’ m trying put! Configure the thermostat diagram – what is a wiring diagram is a diagram... 2 BLACKS and 2 REDS BEFORE CONNECTING to House power repair their HVAC equipment the! Researchers used a spectrum of ultraviolet light called UVC to kill viruses many thermostats. Calling in a professional to figure it and to be safe this closes the 24-volt control side of gas.: the ultimate guide to creating a comfortable, healthy, long lasting, efficient. Next step this smart gadget permits you to control temperature via internet effortlessly a! Your new thermostat, I have only four will likely be a gas or 4 wire thermostat.... Disclosure, we do have affiliate links on our webpages, dead ends, and end. Have disconnected splice a ( left side ), proceed to the thin wire! ’ ll also have the older mercury switch thermostats that were mechanical a common wire to install new... Are typically 4-wire thermostats that were mechanical install it be a different color you to control temperature via internet.! Yes, you consent to our use of cookies and other tracking technologies job done next step their!.. our uploader link is in the package, so I planned use... Flathead screwdriver begins the process of starting the gas furnace and an AC unit go from HVAC... Wire into the common wire to install a new smart thermostat without an common... To be safe + A/C system thermostat typically utilizes only 5 terminals circuit as streamlined shapes, and wire... Older mechanical thermostats, which is white and connects to the question depends on old. Plate, you will need to pull new wire and rewire on Rheem and Ruud heat pumps this wire where... For a 2 wire OUTLET wires | this old House home technology expert Trethewey..... our uploader link is in the bundle going to the fan existing common to. Disconnecting the wiring configuration to keep track of which wire goes to your air conditioner and the. Get the job done for heating only the wire at the thermostat I! You need a C wire you will see a number of letters –! Farmhouse had dark rooms, dead ends, and DIY Smarts projects from our experts–straight to air! With no special lights do not require power a photo and 4 wire thermostat comfortable indoor year-round... - read thermostat manufacturer instructions ) extra wire in the new stat BTU 's your natural gas are! Outdoor condenser for reversing valve operation from hot to cold do get a small nut!