It is very simple and pretty straight forward. } 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. 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. 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. 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 … It terminates in your outdoor condenser for reversing valve operation from hot to cold. Turn on the circuit breaker and test the heater and thermostat for proper op… Unused C Wire Terminal. 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. The orange wire connects to terminal O on your thermostat. Complete the wire connections on the baseboard heater, if this has not already been done. Installing The Wrong Thermostat Type – Always install a thermostat to its compatible base. 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. 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. .top-level { Remove the wall screws holding up the thermostat before disconnecting the wiring to prevent the wires from falling into the wall. Connect the wires. 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. 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 Once the new thermostat is on the wall, turn power back on from the breaker. Thermistors are very simple to wire. Heck, now I’m not calling anyone a dummy! 4-Wire Thermostat Wiring If you have one, that’s your c-wire and you’re ready for general installation. 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 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. Thermistors are also available with metal or plastic cage-style element covers for air temperature measurement. If you must then following these instructions and helpful hints will hopefully help you in this endeavor. Learn more about the  The “18” refers to the gauge and the “5” refers to how many individual wires are inside the cable. Plus, I’m anything but a technician so what I have detailed below is here purely as a guideline. Tuck the wires into the electrical box and secure the thermostat with the mounting screws. Look for a wire connected to a terminal labeled with a “C” on the thermostat. Prevent unplanned production downtime, Measuring Temperatures in Furnaces with Oxidizing Atmospheres, @media screen and (max-width:1024px){ Errors were found with the address you provided. If you have a C wire, place it into the C terminal on your wall plate. Use the wire cutters to strip each wire so that there is approximately 1 inch of bare copper showing. For more advice from our General Contractor reviewer, including tips on how to replace the thermostat in your car, keep reading! Red – Now, there can be two separate wires for this. Snap the thermostat to the mounting plate. Thermostat wire is just a big spool of bundled, color-coded wires. 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. Since the resistance is pretty high (10Kohm) the wire resistance won't make a … 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 wire will run through a dedicated opening on the side of the furnace into the control panel. Connect the remaining supply wire, which is typically white, to the second thermostat wire (typically marked L2 or Line). The wire colors indicate the thermocouple type. Install new thermostat base. Used in three-phase motors. If you have heat and AC, you’ll need 18/5. 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. Tuck the wires into the electrical box and secure the thermostat with the mounting screws. Sometimes they employ a 3-wire construction if a ground or shielding wire is present. The same two wires that connect the thermistor to its excitation source can be used to measure the voltage across the thermistor. You now know how to look for a c wire or common wire in your heating system wiring. I will explain that in a little more detail further down this page. Now, loop each copper end around each terminal, and tighten the screw on the terminal. Even the most seasoned people who enjoy DIY may come across problems with wiring a thermostat. Thermistors are a type of semiconductor, meaning they have greater resistance than conducting materials, but lower resistance than insulating materials. How Do You Wire Your Thermistor? Step 8. AND it has been recorded by a professional in the industry. 5-Wire Thermostat Wiring; This is the most common and covers many central air conditioners with an air handler or gas furnace. Orange – This wire connects to your heat pump (if you have one). 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 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. Thermocouple wires and extension wires are color coded. What is a Thermistor and how does it work? The relationship between a thermistor’s temperature and its resistance is highly dependent upon the materials from which it’s composed. For the Y, Y1, and Y2 wires, Y or Y1 will go to the Y terminal, and Y2 will go to the Y2 terminal. Most come with two-wire connectors. This wire will go to the G terminal on your new thermostat. If your system has both heating and cooling functions, you'll need to connect both the Rc and Rh terminals with a red wire. Tighten the terminal screws to secure the wires in place. The O/B wire can have many configurations. The thermostat wiring on these systems can have very similar wiring properties. 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. Connect each marked wire to the corresponding terminals on the thermostat with a screwdriver. The orange wire only applies to … Screw the system wiring to the screw terminals on the new thermostat using the letter labels as reference (strip the wires back if necessary). 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. Unscrew and remove the wires from their terminals. Thermostat Center is supported by our readers. Wrapping old wire in electric tape protects you and the system from any type of past or future damage. Please verify your address. Green – The green wire connects to the fan. Fiberglass insulation is great for preventing drafts from affecting thermostat operation. Using wire connectors, connect a hot supply wire, which is typically black, to thermostat wire one (typically it is marked L1 or Line). Run the thermostat wire from your furnace to the location where your thermostat will hang. Depending on the thermocouple’s type, a thermocouple’s wires may be magnetic. 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). One is for cool and the other is for heat, hence the abbreviation “RH” and “RC”. Running new thermostat wire can challenging even for professionals. Mount the baseplate of the smart thermostat to the wall using the provided screws. Use a small screwdriver to loosen the terminal screws on the Sensi thermostat base, and insert each labeled wire into the corresponding terminal. Complete the wire connections on the baseboard heater, if this has not already been done. White – The white wire is what connects to the (auxiliary) heat on your system. Drill a hole in the drywall, and use a fishtape to feed the wire from the furnace through the hole in the wall.