How to Hook Up a Thermostat: Hook up the wires. Installing The Wrong Thermostat Type – Always install a thermostat to its compatible base. Complete the wire connections on the baseboard heater, if this has not already been done. Running new thermostat wire can challenging even for professionals. The thermostat uses 1 wire to control each of your HVAC system’s primary functions, such as heating, cooling, fan, etc. Connect the wires to the terminals. 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 Mount the control unit to the base using the screws included with your thermostat. You now know how to look for a c wire or common wire in your heating system wiring. The “18” refers to the gauge and the “5” refers to how many individual wires are inside the cable. Tuck the wires into the electrical box and secure the thermostat with the mounting screws. 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. The orange wire connects to terminal O on your thermostat. 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. HSTH-44000. If you have heat and AC, you’ll need 18/5. The same two wires that connect the thermistor to its excitation source can be used to measure the voltage across the thermistor. The thermistor has to be connected to a control circuit, which can convert the resistance signal, which again has to disconnect the motor. 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 … Red – Now, there can be two separate wires for this. Most come with two-wire connectors. Turn on the circuit breaker and test the heater and thermostat for proper operation. Install new thermostat base. If you have a C wire, place it into the C terminal on your wall plate. Wrapping old wire in electric tape protects you and the system from any type of past or future damage. Thermistors are a type of semiconductor, meaning they have greater resistance than conducting materials, but lower resistance than insulating materials. 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. Depending on the thermocouple’s type, a thermocouple’s wires may be magnetic. 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. 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. Complete the wire connections on the baseboard heater, if this has not already been done. Prevent unplanned production downtime, Measuring Temperatures in Furnaces with Oxidizing Atmospheres, @media screen and (max-width:1024px){ Connect the wires. } Track when you leave the house (or workplace) and are away regularly for … Thermostat wire is just a big spool of bundled, color-coded wires. Used in three-phase motors. How Do You Wire Your Thermistor? The wire will run through a dedicated opening on the side of the furnace into the control panel. Wire the smart thermostat to the correct terminals. This wire will go to the G terminal on your new thermostat. For more advice from our General Contractor reviewer, including tips on how to replace the thermostat in your car, keep reading! Thermostat wire comes in various weights. It is very simple and pretty straight forward. overflow:hidden; Learn more about the  8. Orange – This wire connects to your heat pump (if you have one). Using wire connectors, connect a hot supply wire, which is typically black, to thermostat wire one (typically it is marked L1 or Line). 4-Wire Thermostat Wiring Heck, now I’m not calling anyone a dummy! Green – The green wire connects to the fan. Even the most seasoned people who enjoy DIY may come across problems with wiring a thermostat. The manufacturer typically determines this property with a high degree of accuracy, as this is the primary characteristic of interest to thermistor buyers. What is a Thermistor and how does it work? 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. The wire colors indicate the thermocouple type. 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. Unscrew and remove the wires from their terminals. Unused C Wire Terminal. Snap the thermostat to the mounting plate. 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. The O/B wire can have many configurations. Remove the wall screws holding up the thermostat before disconnecting the wiring to prevent the wires from falling into the wall. For the Y, Y1, and Y2 wires, Y or Y1 will go to the Y terminal, and Y2 will go to the Y2 terminal. Once the new thermostat is on the wall, turn power back on from the breaker. Tuck the wires into the electrical box and secure the thermostat with the mounting screws. 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. I will explain that in a little more detail further down this page. Thermocouple wires and extension wires are color coded. Sometimes they employ a 3-wire construction if a ground or shielding wire is present. Reviews and General Information on Programmable Thermostats. Use the wire cutters to strip each wire so that there is approximately 1 inch of bare copper showing. Run the thermostat wire from your furnace to the location where your thermostat will hang. View this page in another language or region, Learn more about the  5-Wire Thermostat Wiring; This is the most common and covers many central air conditioners with an air handler or gas furnace. Install the replacement wall plate and hook the new thermostat up to the old wires. 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. The video below will help you install your thermostat if you do not have a c wire. Thermistors are also available with metal or plastic cage-style element covers for air temperature measurement. Look for a wire connected to a terminal labeled with a “C” on the thermostat. The thermostat wiring on these systems can have very similar wiring properties. Screw the system wiring to the screw terminals on the new thermostat using the letter labels as reference (strip the wires back if necessary). Fiberglass insulation is great for preventing drafts from affecting thermostat operation. Thermostat Center is supported by our readers. Let's take a look at the G wire. }, Copyright 2003 - 2019 OMEGA Engineering is a subsidiary of Spectris plc. I hope that was very clear! Now, loop each copper end around each terminal, and tighten the screw on the terminal. Of course you can cut or extend the wires. 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. Thermostat Wiring for Dummies. 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). Do not let them fall back in through the hole in … Plus, I’m anything but a technician so what I have detailed below is here purely as a guideline. Step 8. These letters are standard; hook them up to the same terminals on the new thermostat. One is for cool and the other is for heat, hence the abbreviation “RH” and “RC”. Safe and precise temperature transmission and control can prevent unplanned production downtime When you purchase an item through links on our site, we may earn an affiliate commission. 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. Turn on the circuit breaker and test the heater and thermostat for proper op… Mount the baseplate of the smart thermostat to the wall using the provided screws. 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. Thermistor motor protection. 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. Yellow – The yellow wire connects to your compressor. 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. Please verify your address. White – The white wire is what connects to the (auxiliary) heat on your system. Tighten the terminal screws to secure the wires in place. The orange wire only applies to … Use a small screwdriver to loosen the terminal screws on the Sensi thermostat base, and insert each labeled wire into the corresponding terminal. Connect the remaining supply wire, which is typically white, to the second thermostat wire (typically marked L2 or Line). .top-level { Since the resistance is pretty high (10Kohm) the wire resistance won't make a … Even the most seasoned people who enjoy DIY may come across problems with wiring a thermostat. 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. Connect each marked wire to the corresponding terminals on the thermostat with a screwdriver. 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. Heck, now I’m not calling anyone a dummy! 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. Step 9. It terminates in your outdoor condenser for reversing valve operation from hot to cold. Determine your schedule. AND it has been recorded by a professional in the industry. C wire from furnace to thermostat – Source. If you have one, that’s your c-wire and you’re ready for general installation. Drill a hole in the drywall, and use a fishtape to feed the wire from the furnace through the hole in the wall. 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). They have very low resistance (compared to RTDs and thermistors.) Tighten the screws securely. If your system has both heating and cooling functions, you'll need to connect both the Rc and Rh terminals with a red wire. 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