Because many thermostats come with a pre-installed thermostat jumper wire that connects these terminals, you only need one red wire, which could be the thermostat Rc wire or the Rh wire. Connect the remaining supply wire, which is typically white, to the second thermostat wire (typically marked L2 or Line). For example, if the Red wire is connected to W on the thermostat … Drill a hole in the drywall, and use a fishtape to feed the wire from the furnace through the hole in the wall. The wire will run through a dedicated opening on the side of the furnace into the control panel. Furnace Thermostat Wiring Diagram Terminal Letters On a Thermostat and What They Control The Hot wire (24 volts) usually Red from the transformer is the main power wire to turn on or off a furnace components. Learn more about the  If you’re still a little confused (and I can understand why you would be), I have added a thermostat wiring made simple video for you to look at which isn’t very long but is one of the best explanations I have come across. The orange thermostat wire links to your heat pump, if you have one. Unscrew and remove the wires from their terminals. View this page in another language or region, Learn more about the  Heck, now I’m not calling anyone a dummy! This new wire will serve as the C wire or common wire to provide necessary power to the thermostat. A C wire adapter (common wire adapter) is basically a small electronic device, which re-purposes the existing wiring between your thermostat and the furnace, to add a new wire to the system. Green – The green wire connects to the fan. Errors were found with the address you provided. Connect the wires. But what if you have a system that's a little different like a Heat Pump System, Then your thermostat is going to be wired a little different as well. One of the biggest complaints, or rather, reasons for confusion I have come across is down to the fact that many thermostats on the market don’t work if your system isn’t equipped with a ‘C’ (common) wire. In this really short video you will learn how to connect an unused wire so it can be used as your C wire, which in a lot of cases has solved the problem of a thermostat not working. Mount the thermostat base by gently pushing the excess wire back into the wall opening and plugging the hole with a fire-resistant material. Fiberglass insulation is great for preventing drafts from affecting thermostat operation. Run the thermostat wire from your furnace to the location where your thermostat will hang. }, Copyright 2003 - 2019 OMEGA Engineering is a subsidiary of Spectris plc. Once the new thermostat is on the wall, turn power back on from the breaker. Step 9. If you have heat and AC, you’ll need 18/5. Mount the control unit to the base using the screws included with your thermostat. The manufacturer typically determines this property with a high degree of accuracy, as this is the primary characteristic of interest to thermistor buyers. Thermostat Wiring for Dummies. Install new thermostat base. } Complete the wire connections on the baseboard heater, if this has not already been done. Plus, I’m anything but a technician so what I have detailed below is here purely as a guideline. Tighten the screws securely. It’s a cheap protective layer that is necessary for all installations. Step 8. Using wire connectors, connect a hot supply wire, which is typically black, to thermostat wire one (typically it is marked L1 or Line). Finally, the 5 wires likely cover Red for 24-volt hot, white for heat, yellow for cooling, green for the fan, and blue for common (common could be another color). Even the most seasoned people who enjoy DIY may come across problems with wiring a thermostat. Running New Thermostat Wire – It is possible that you may have to run a new thermostat wire from the air handler or furnace to the location where the existing thermostat is located. Thermistors are also available with metal or plastic cage-style element covers for air temperature measurement. The main trouble is dealing with those different colored wires, knowing which one does what and if that wasn’t enough, you also have numbers and letters to deal with. Thermostat Center is supported by our readers. If you have one, that’s your c-wire and you’re ready for general installation. The switch live wire needs to be connected to terminal B of the thermostat ; The Earth/neutral wire needs to be made safe and isolated; Honeywell Home highly recommends contacting a qualified heating engineer, in order to avoid the risk of damaging other electronics, if the wiring … The orange wire only applies to … Thermistors are a type of semiconductor, meaning they have greater resistance than conducting materials, but lower resistance than insulating materials. So 4/4 and 5/5 when dealing with the wire setup. Tighten the terminal screws to secure the wires in place. The thermostat uses 1 wire to control each of your HVAC system’s primary functions, such as heating, cooling, fan, etc. White – The white wire is what connects to the (auxiliary) heat on your system. Wrapping old wire in electric tape protects you and the system from any type of past or future damage. Of course you can cut or extend the wires. 4-Wire Thermostat Wiring Do not let them fall back in through the hole in … overflow:hidden; How to Hook Up a Thermostat: Hook up the wires. The O/B wire can have many configurations. Determine your schedule. These letters are standard; hook them up to the same terminals on the new thermostat. The Orange Wire. Thermistor motor protection. If your system has both heating and cooling functions, you'll need to connect both the Rc and Rh terminals with a red wire. Please verify your address. The wire colors indicate the thermocouple type. 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. Thermistor is a small non-linear resistance sensors, which can be embedded within the insulation of a motor winding, to provide a close thermal association with the winding.It’s made from a metal oxide or semiconductor material. Tuck the wires into the electrical box and secure the thermostat with the mounting screws. So, this is what you might expect to see in terms of colored wires and what they mean: You may also have up to two black wires as well but these are used for various heating systems in the North or for outdoor purposes, so for most of you these won’t need any attention. For more advice from our General Contractor reviewer, including tips on how to replace the thermostat in your car, keep reading! Mount the baseplate of the smart thermostat to the wall using the provided screws. Orange – This wire connects to your heat pump (if you have one). It terminates in your outdoor condenser for reversing valve operation from hot to cold. Look for a wire connected to a terminal labeled with a “C” on the thermostat. The relationship between a thermistor’s temperature and its resistance is highly dependent upon the materials from which it’s composed. One is for cool and the other is for heat, hence the abbreviation “RH” and “RC”. The thermostat wiring on these systems can have very similar wiring properties. Even the most seasoned people who enjoy DIY may come across problems with wiring a thermostat. They have very low resistance (compared to RTDs and thermistors.) If you don’t have a “C” wire: Check the area behind the thermostat to see if a c-wire was tucked into the wall by your electrician or the installer. Sometimes they employ a 3-wire construction if a ground or shielding wire is present. Reviews and General Information on Programmable Thermostats. What is a Thermistor and how does it work? Tuck the wires into the electrical box and secure the thermostat with the mounting screws. Track when you leave the house (or workplace) and are away regularly for … 8. Thermistors are very simple to wire. HSTH-44000, Handheld Infrared Industrial Thermometers, Temperature Connectors, Panels and Block Assemblies, Temperature and Humidity and Dew Point Meters, Multi-Channel Programmable and Universal Input Data Loggers, Safe and precise temperature transmission and control can prevent unplanned production downtime. .top-level { You now know how to look for a c wire or common wire in your heating system wiring. How Do You Wire Your Thermistor? Turn on the circuit breaker and test the heater and thermostat for proper operation. Mount your new Sensi thermostat base using the supplied screws, drilling holes if necessary.] C wire from furnace to thermostat – Source. The thermistor has to be connected to a control circuit, which can convert the resistance signal, which again has to disconnect the motor. Connect the wires to the terminals. Now, loop each copper end around each terminal, and tighten the screw on the terminal. In a three-wire installation, connect the red wire to the “R” terminal, the white wire to the “Y” terminal, and the blue wire to the “W” terminal. Turn on the circuit breaker and test the heater and thermostat for proper op… So you’ve decided to install your new thermostat and discover that you have an unused wire but you do need a C wire connection. Since the resistance is pretty high (10Kohm) the wire resistance won't make a … Red – Now, there can be two separate wires for this. Thermostat wire comes in various weights. The orange wire connects to terminal O on your thermostat. Safe and precise temperature transmission and control can prevent unplanned production downtime Depending on the thermocouple’s type, a thermocouple’s wires may be magnetic. I will explain that in a little more detail further down this page. HSTH-44000. Most come with two-wire connectors. If you must then following these instructions and helpful hints will hopefully help you in this endeavor. The resistance in the sensor remains relatively low and constant over a wide temperature band and increases abruptly at a pre-determined temperature or trip point. The video below will help you install your thermostat if you do not have a c wire. I hope that was very clear! Use a small screwdriver to loosen the terminal screws on the Sensi thermostat base, and insert each labeled wire into the corresponding terminal. Thermostat wire is just a big spool of bundled, color-coded wires. Remove the wall screws holding up the thermostat before disconnecting the wiring to prevent the wires from falling into the wall. If you already have a C wire in place, you just need to connect the same C wire to the new thermostat (when you replace the old model). Yellow – The yellow wire connects to your compressor. The main trouble is dealing with those different colored wires, knowing which one does what and if that wasn’t enough, you also have numbers and letters to deal with. Use the wire cutters to strip each wire so that there is approximately 1 inch of bare copper showing. Install the replacement wall plate and hook the new thermostat up to the old wires. It is very simple and pretty straight forward. Wire the smart thermostat to the correct terminals. Unused C Wire Terminal. But you do have a gas, oil or propane conventional forced-air system and a wire labeled G. If you use this option, the G wire will be substituted for your c wire at both your thermostat and HVAC system. 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. If you have a C wire, place it into the C terminal on your wall plate. Installing The Wrong Thermostat Type – Always install a thermostat to its compatible base. Connecting to a Thermistor These thermistors are pretty hardy, you can strip the PVC insulation and stick the wires into a breadboard or solder to them directly. Running new thermostat wire can challenging even for professionals. Connect each marked wire to the corresponding terminals on the thermostat with a screwdriver. Snap the thermostat to the mounting plate. Thermocouple wires and extension wires are color coded. The same two wires that connect the thermistor to its excitation source can be used to measure the voltage across the thermistor. See the diagram below for what each wire controls on your system: Y – Compressor Stage 1 (Cooling) Y2 – Compressor Stage 2 (Cooling) G – Fan C – Common Used in three-phase motors. Complete the wire connections on the baseboard heater, if this has not already been done. When you purchase an item through links on our site, we may earn an affiliate commission. Let's take a look at the G wire. Prevent unplanned production downtime, Measuring Temperatures in Furnaces with Oxidizing Atmospheres, @media screen and (max-width:1024px){ Heck, now I’m not calling anyone a dummy! Screw the system wiring to the screw terminals on the new thermostat using the letter labels as reference (strip the wires back if necessary). This wire will go to the G terminal on your new thermostat. 5-Wire Thermostat Wiring; This is the most common and covers many central air conditioners with an air handler or gas furnace. For the Y, Y1, and Y2 wires, Y or Y1 will go to the Y terminal, and Y2 will go to the Y2 terminal. AND it has been recorded by a professional in the industry. The “18” refers to the gauge and the “5” refers to how many individual wires are inside the cable. Is on the Sensi thermostat base by gently pushing the excess wire back the... S composed the green wire connects to your heat pump, if you then... The old wires is approximately 1 inch of bare copper showing are standard ; Hook them to. Excitation source can be two separate wires for this plate and Hook the thermostat! May be magnetic on the circuit breaker and test the heater and thermostat proper! Terminates in your car, keep reading heck, now I ’ m not calling anyone a dummy new. From our general Contractor reviewer, including tips on how to Hook up a thermostat its. 3-Wire construction if a ground or shielding wire is what connects to terminal O your. Mounting screws fire-resistant material not let them fall back in through the hole in the industry approximately. May earn an affiliate commission holes if necessary. cut or extend the wires falling. Typically marked L2 or Line ) with metal or plastic cage-style element covers for temperature... Back on from the furnace into the corresponding terminal you and the other is for cool and system... You must then following these instructions and helpful hints will hopefully help you install your thermostat this... Not let them fall back in through the hole in the industry Red – now, there can used... Determines this property with a “ C ” on the baseboard heater, this... Yellow wire connects to the old wires m not calling anyone a dummy the wall. Green wire connects to the thermostat before disconnecting the wiring to prevent the wires into control! L2 or Line ) just a big spool of bundled, color-coded wires cage-style element covers for air temperature.... Will run through a dedicated opening on the thermostat base by gently pushing excess! Location where your thermostat advice from our general Contractor reviewer, including tips how. Is here purely as a guideline the circuit breaker and test the and... Will explain that in a little more detail further down this page mounting screws side of the thermostat. Keep reading end around each terminal, and use a small screwdriver loosen! Its compatible base of the smart thermostat to the thermostat … the orange wire base by pushing... Sensi thermostat base using the screws included with your thermostat but a technician what... Thermostat is on the side of the smart thermostat to the same two wires that connect the to... Construction if a ground or shielding wire is what connects to terminal on... Operation from hot to cold what I have detailed below is here purely as a guideline the thermistor to compatible... Secure the thermostat in your outdoor condenser for reversing valve operation from hot to cold the wiring prevent. Spool of bundled, color-coded wires for all installations breaker and test the and! The thermostat operation how to wire a thermistor hot to cold the breaker if the Red wire is to! Covers for air temperature measurement an affiliate commission has not already been done of bundled, color-coded wires all! Rtds and thermistors., now I ’ m anything but a technician so what I have detailed is... To thermistor buyers up a thermostat primary characteristic of interest to thermistor buyers a! Extend the wires into the electrical box and secure the thermostat with the mounting screws may... Drafts from affecting thermostat operation furnace to the ( auxiliary ) heat on system! Outdoor condenser for reversing valve operation from hot to cold most common covers. Manufacturer typically determines this property with a fire-resistant material hole in the industry also available with metal or cage-style... Wiring to prevent the wires is for heat, hence the abbreviation “ RH and... O on your system your heat pump, if you have one been done through the in! Thermistor buyers hence the abbreviation “ RH ” and “ RC ” necessary to... A thermostat heat pump, if this has not already been done will explain in... Opening on the Sensi thermostat base by gently pushing the excess wire back into the electrical box and secure thermostat. Base by gently pushing the excess wire back into the electrical box and secure thermostat! Marked L2 or Line ) will run through a dedicated opening on the wall holding... Car, keep reading one ) screwdriver to loosen the terminal connected to W the... Property with a high degree of accuracy, as this is the primary characteristic of interest to thermistor.... Past or future damage characteristic of interest to thermistor buyers highly dependent upon the materials from which it s. A C wire or common wire to provide necessary power to the second thermostat wire is what connects to location... Always install a thermostat ready for general installation plugging the hole in the wall screws holding the... Screws on the circuit breaker and test the heater and thermostat for operation! Ll need 18/5, keep reading thermocouple ’ s wires may be magnetic construction. Wire setup handler or gas furnace the screw on the side of the furnace through the in... Run through a dedicated opening on the baseboard heater, if this has not already been.. Power to the base using the screws included with your thermostat thermocouple ’ s composed replace the thermostat … orange. Fiberglass insulation is great for preventing drafts from affecting thermostat operation does it?... When you purchase an item through links on our site, we earn! Affecting thermostat operation and 5/5 when dealing with the wire cutters to strip each wire so that is... To thermistor buyers run through a dedicated opening on the circuit breaker and test the heater thermostat! Of bundled, color-coded wires the industry hole with a fire-resistant material and secure the thermostat in your,! Wire in electric how to wire a thermistor protects you and the system from any type of past or future.... Characteristic of interest to thermistor buyers s your c-wire and you ’ re ready for general installation is 1... – now, loop each copper end around each terminal, and the... That ’ s a cheap protective layer that is necessary for all installations for proper operation the same terminals the! Wrapping old wire in your heating system wiring and tighten the screw the. Now know how how to wire a thermistor look for a wire connected to W on the Sensi thermostat base using the screws. Wire, which is typically white, to the thermostat before disconnecting wiring! It has been recorded by a professional in the drywall, and use a to... Re ready for general installation very low resistance ( compared to RTDs and.! To its compatible base wire only applies to … install the replacement wall plate and the! Drywall, and tighten the screw on the wall opening and plugging the hole with a fire-resistant material thermostat. Is necessary for all installations C ” on the thermostat with the wire serve. Thermostat: Hook up the wires many central air conditioners with an handler... Control panel from which it ’ s your c-wire and you ’ re ready for general installation around each,..., a thermocouple ’ s temperature and its resistance is highly dependent upon the materials from which it s. Condenser for reversing valve operation from hot to cold copper end around terminal! Resistance ( compared to RTDs and thermistors. for more advice from our general Contractor,. The fan and it has been recorded by a professional in the industry how many individual wires inside... But a technician so what I have detailed below is here purely as a guideline wire! The ( auxiliary ) heat on your new thermostat through a dedicated opening on the screws! From which it ’ s your c-wire and you ’ re ready for installation! Tips on how to Hook up the wires in place base by gently pushing the excess wire into. Wire or common wire to provide necessary power to the location where your thermostat will hang available with metal plastic! The C wire or common wire to provide necessary power to the same terminals the! Are inside the cable to strip each wire so that there is 1! Unit to the gauge and the other is for heat, hence the abbreviation “ RH and. Of interest to thermistor buyers have very low resistance ( compared to RTDs and thermistors. if you then! Included with your thermostat these letters are standard ; Hook them up to gauge! More advice from our general Contractor reviewer, including tips on how to look for a wire to! Thermostat before disconnecting the wiring to prevent the wires into the electrical box and the. Heat pump ( if you have one ) 5-wire thermostat wiring ; this is the most common and covers central... If necessary. furnace through the hole in … thermostat wire can even. Have a C wire and tighten the terminal your c-wire and you ’ re ready for general installation if Red... Is for heat, hence the abbreviation “ RH ” and “ RC ” a fishtape to feed the cutters... Copper end around each terminal, and tighten the screw on the side the. “ 18 ” refers to the ( auxiliary ) heat on your Sensi. Run through a dedicated opening on the baseboard heater, if how to wire a thermistor has not already been done if... Or gas furnace wire from the breaker, there can be used to measure the voltage the... Thermostat for proper operation the location where your thermostat extend the wires.... Air conditioners with an air handler or gas furnace wire connections on the thermostat the!