Get the App Here:
Download the free Total Connect Comfort app on Google Play or Apple Store for either Apple or Android devices to control your thermostat from anywhere.
Watch a series of short videos that help you install your thermostat, including determining your system type, the installation process in steps, registering your thermostat and more.See Video’s Below.
Quick Start Manuals & Guides PDF
Download PDFs of manuals and guides in the resources section below, such as Quick Start and User Guides.
An extra unused wire in the wall can be used as the C wire for your new thermostat. The extra wire will also need to be connected to the C (common) terminal at the heating and cooling system. This will provide power to your new thermostat.
Please note that the C-wire is only needed for Wi-Fi connected thermostats [click here to see our Wi-Fi thermostats]. Most standard thermostats do not need a C-wire.
Please refer to the videos below for more information:
What Is a C-Wire?
What if I Don't Have a C-Wire?
The C wire is another name for the Common wire. There is no universal color used to designate this type of wire. It is simply a wire that originates from your heating/cooling system and needs to be connected to the C terminal on your Lyric, Wi-Fi or connected thermostat. The purpose of the C wire is to provide constant 24-volt power to the thermostat.
Not all thermostats need a C wire, although use of Apple HomeKit with your thermostat and most Wi-Fi enabled thermostats do require one. The Honeywell Lyric Round Wi-Fi Thermostat is the one exception to the Wi-Fi, smart, connected thermostat rule, as it does not require a C wire. It can still function by drawing power from your heating and cooling systems to power its battery. This method is also referred to as Phantom Power or Power Stealing. Honeywell also offers a wide variety of non-connected thermostats that do not require a C wire to operate.
If a C wire is required for your thermostat install, please read: What options do I have if I don't have the "C" or common wire?
For more information on the C wire topic, please watch this instructional video:
Your old thermostat model may not have required a wire connected to a C terminal. Honeywell offers many great non-connected thermostats that do not require the need for a C wire to power the device. Most of these thermostats are powered by basic AAA or AA batteries.
The C wire or Common wire is necessary to provide 24-volt power to your Honeywell Wi-Fi or connected thermostat (exception is the Lyric Round) and for use with Apple HomeKit.
If this wire is not plugged into the C terminal, and you want to know if you have one or not, be sure to check if there is an extra wire that is pushed into the wall or wrapped around the wire bundle coming from the wall. Gently pull on the wire bundle to check whether there are any additional wires.
If you do find an extra wire, you can try connecting it to your thermostat's C terminal, but you must also ensure that the same wire is connected at the furnace's terminal panel. Please review our Thermostat Wiring Compatibility page for pictures and step by step instruction to confirm that your system meets compatibility requirements.
If you do not have a C wire and need one to power your Wi-Fi or connected thermostat, there are several options like using a Honeywell Wire Saver Module, a thermostat that uses phantom power or the G wire solution. Please view, What options do I have if I don't have the "C" or common wire? for additional information.
For directions and alternative wiring options, please refer to this instructional video:
Yes, any Honeywell connected or Wi-Fi thermostat requires a wire connected to the C terminal to power the thermostat.
If you do not have a C wire, there are several options that you can choose from in order to make your Honeywell Wi-Fi thermostat functional. Please see What options do I have if I don't have the "C" or Common wire? for more information.
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