Smart Thermostats that Don’t Use a C-Wire

Knowing Your Options


December 10, 2020

22Smart Thermostats1

Smart thermostats have become a social norm. They aren’t only convenient, but are also energy efficient and transitioning into green living has never been easier. However, some do not use C-Wire, or common wire. However, there are other options available to the energy-efficient homeowner.

What is C-wire?

C-wire is also called common wire. The connection enables 24/7 VAC power to your thermostat. If you have one already, it runs from your furnace to your thermostat.

To find out of you have a C-wire, you can check using the following steps:

  • You will need to contact your HVAC technician to ensure you have a low voltage system. Online resources are a great help if you feel more comfortable trying to resolve the issue with as little help as possible.

  • Take your thermostat off the wall. The C-wire could be blue, but it could also be green, yellow, or even black. When you read your manual, it will lead you to the C-wire, or tell you that you do not have one.

  • If you do not see the C-wire instantly, check behind the thermostat. The wire is likely rolled up behind the wall.

  • If you find no wire, then you do not have a C-wire. However, there are subsequent steps you can take if this is the case.

Optimizing options without C-wire

  • Not all options are as simple as a DIY explanation. With that said, if you know what you are doing, you can replace the existing wiring that runs from the furnace to thermostat and replace it with a new installation that suits your needs. The distance may be short, making the job easy. But, if you feel like this is a complicated process, please call a technician.

  • Add-on adapters are available, with most being relatively inexpensive. Installing an adapter is rather straightforward and allows you to have the smart thermostat you want, and you do not already have the wiring for the future with a C-wire.

  • Some thermostats come with adapters already in place. The smart appliance is easy to install and use. But it is not for everyone. You may still want to pursue an adapter for your existing thermostat, rather than buying a new one altogether.

There are smart thermostats available that do not require a C-wire at all. This option may end up being a little pricier than others, so it all depends on personal preference.

To C-Wire or not to C-Wire

Every heating and cooling system is different. The first step will always be figuring out what category of thermostat you currently own and use and then determining if you’re comfortable tinkering with it yourself.

Most, if not all, smart thermostat manufacturers have a helpline you can call for personalized support, too, so give them a call if you’re truly stumped. You will also want to research and ensure that manufacturer has the parts and replacement parts you will require down the road.

Smart thermostats can enhance your home’s energy efficiency and save you money. For more information, about smart thermostats and how they can fit into a smart security system, call Brinks Home™ today for a free quote.

Lauren Slade is a Dallas-based writer and editor.

iOT Home Security

IOT Home Security: Everything You Need to Know

Read more
Smart Home Automation

Home Security & Automation: How They Work Together

Read more
17 Smart Home Technology1

Smart Home Technology

Read more
Share via:

We are not able to service your area yet.

Thank you...

Your request has been submitted.

One of our expert security consultants will be in touch. Together, we'll design a smart home security system to fit your lifestyle.


Interested in a Home Security System?

Complete this form and a Brinks Home™ Security Consultant will reach out regarding building your security system.

...or Call 888.627.3631

By clicking the ‘Submit’ above below, I agree that a Brinks Home specialist may contact me via text messages or phone calls to the phone number provided by me using automated technology about Brinks Home offers. This consent is not required to make a purchase. Your information is collected and used in accordance with our privacy policy. Clicking the button below constitutes your electronic signature.