Thermostat Wiring Diagrams! HVAC systems with more functions need more wires to communicate to and from the thermostat. The thermostat uses 1 wire to control each of your HVAC system’s primary functions, such as heating, cooling, fan, etc. Related Post: How to Wire Non-Simultaneous 240V Water Heater Thermostat? 1. Alternative Thermostat wiring for Furrion Chill RV AC. The red wire is hot. There would be two installation options; 2 fan speed using the existing 5 wires, for 3 fan speed installation we would also need to install a wire saver module that provides the required 6th wire. You just bought a new thermostat but which wire goes where? I've read that I might have blown the Step Down Transformer but I don't know where that is located to replace it. A common wire (C-Wire) provides Wi-Fi thermostats continuous power by connecting it to a heating and cooling system (e.g. I was an idiot and did not take a picture of the wiring on my previous thermostat when I went to install the Nest. The common wire links to the C terminal. Rc wires are only for air conditioning systems or dual transformer systems. If you need help installing your new thermostat, Aire Serv® is here to help you get it right. The common wire doesn’t have a standard color. Traditional HVAC wiring in homes uses four or more wires, one of which is called the “common” wire or c-wire. Call (855) 679-0011 or request an appointment online to get started. 1 Heat / 1 Cool Thermostat. While some units can run without a c-wire, even brands like Nest recommend having one for optimal function. I have a Green, White, Black, and Red wire. 3-wire thermostat wiring: This type of wiring is for thermostats that controls a boiler. Read on for information about all possible thermostat wires. C-Wires are required on most Honeywell Wi-Fi thermostats, with the exception of the Smart Round Thermostat (formerly known as the Lyric Round). The orange wire connects to terminal O on your thermostat. See the diagram below for what each wire controls on your system: S – Indoor and Outdoor Wired Sensors. Red/Rh – if you don’t have an Rc wire (described below), the Rh wire is the power wire for both – heating and cooling systems. For the 3 conductor communications cable installation the wire colors or the cable match connect the orange wire from the szlcd thermostat comms terminal to the orange wire that runs from the szlcd control relay box. One thing to be aware of is that most thermostats control the equipment with thin low-voltage wires (24V) which are not particularly dangerous, but some electric heat has line-level voltage going to the thermostat (normal electricity wires, 120V or 240V) which needs to be properly installed like any other live electric wire. It terminates in your outdoor condenser for reversing valve operation from hot to cold. The thermostat uses 1 wire to control each of your HVAC system’s primary functions, such as heating, cooling, fan, etc. I do not use the cooling part of the Tstat (no AC). Colors, Terminals, Functions, Voltage Path! The green wire connects to terminal G on your thermostat. Rc wires connect to the RC terminals on your thermostat. Although I’ve seen it stated in several places, it’s not entirely correct to say that the c-wire is what powers the thermostat. I appreciate all the comments, questions, and responses that I receive from each of you. Orange – This wire connects to your heat pump (if you have one). Aire Serv can help homeowners with all thermostat and HVAC needs. By the use of an adjustable set-point, the job of the thermostat is to turn on either the heating or cooling system to maintain the desired room temperature in the home, and to turn off the system when the desired temperature is achieved. They provide a source of 24V power coming from the HVAC control board. roof top air conditioner and any furnace with a 12 VDC control circuit. Featuring solid, bare-copper conductors and 6 miles of PVC insulation, this wire is … This means that if the humidistat is in the set range and the thermostat temperature is below range the AC and humidifier won’t kick in. Most models follow a thermostat color code for ease of use, key in telling you which wires to connect to which terminals. The yellow wires terminate at your compressor contactor via an air handler. © 2021 Dwyer Franchising, LLC All rights reserved. The C-Wire Power Adapter makes Honeywell Home smart thermostats compatible with most homes that don’t have this wire. CSA Lead Wire. Furnace and AC (color coded) 1 Heat / 1 Cool Thermostat. Six-wire thermostats are typical with heating systems that have two stages of heat and one stage of air conditioning. Although there are some options available if you do not have a ‘C’ wire (see below), having one opens up a much greater choice. Only air-source heat pumps connect to your outdoor condenser. No yellow. 1. If the air conditioning thermostat has one transformer to power both the heating and cooling system, then the wire from the transformer goes directly to the RC terminal and is called the RC wire. They control your air conditioning system. The green wire underneath your thermostat connects to the fan of your furnace or air handler. In standard thermostat wiring, the blue wire connects to the common terminal on the thermostat, making it the C-wire. How Thermostats Work . Parallel wiring, … Thermostat Wiring Diagrams for Heat Pumps - Heat Pump Thermostat Wire Diagrams. If you have heat and AC, you’ll need 18/5. Step 2: Label where the wires are connected on the thermostat.Check to see if they match the industry standard listed above. It was wired up with an thermostat that does both heat and cooling. In heat pump system, there are at least 8 wires that need to be connected to the Heat pump thermostat wiring - A typical wire color and terminal diagram. White – The white wire is what connects to the (auxiliary) heat on your system. Although it may seem tedious and challenging to most, including novice electricians, completing a thermostat replacement project in your home can be quite simple. All possible thermostat wires the basics layout of a C wire doesn ’ t carry! Install the Nest a boiler of Nest with 5 wire Midea AC is possible or dual transformer setup use cooling! Can help increase energy efficiency when running your furnace and air conditioner or air conditioner and furnace... Your heat pump, if you do have an Rh and an Rc wire, Rh. For reversing valve operation from hot to cold and one stage of air conditioning to check you... Might have blown the step down transformer but i do not use cooling... 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