I Want a Smart Thermostat but Don't Have a C Wire - Now What?

June 09, 2021

When you’re seeking approaches to reduce heating and cooling costs, upgrading to a smart thermostat is an intelligent idea. These devices learn your temperature preferences and routine and then create an energy-efficient schedule to match. What’s even better is that you can adjust and watch your settings from nearly anywhere with your phone, whether you’re sitting in bed or out and about. (You might even be eligible for a free smart thermostat depending on rebate programs from your utility supplier in Middle Georgia.)

In most instances, hooking up a smart home thermostat with the support of Air Concepts of Middle Georgia is an uncomplicated job if you have a newer home. But what if your home is older or doesn’t have the proper wiring? Can you still have a smart thermostat without C wire? We’ll help you demystify the process so you can choose the proper thermostat and get energy savings for many years.

What Is a C Wire and What Does It Do on a Thermostat?

The majority of programmable thermostats need batteries. When you’re making the move to a smart thermostat, you’ll find that many require a C wire, or common wire, for power. Without this wire, your new thermostat may cause your heating and cooling system to have glitches.

You can determine if you have a C wire by doing the following:

  1. Cut power to the thermostat at the breaker.
  2. Remove the thermostat and find the wiring.
  3. If there are five or six multicolored wires, you have what’s required for a smart thermostat. You might be thinking what color is the C wire on a thermostat—and the answer to that is often blue.
  4. If there are three or four thin multicolored wires, you’re nearly there. Make sure the C wire isn’t hidden in the wall. If you can’t find one, we may be able to put in one for you or you may be able to operate your new thermostat without one.
  5. If you have two thick wires, you may be able to use a smart thermostat with an adaptor designed for high-voltage systems. Or you may be able to install a battery-powered smart thermostat, like the Lux Geo Wi-Fi Thermostat, if your wiring is incompatible and you don’t want to replace it.

Do Nest or ecobee Need a C Wire?

Two of the most popular brands are the Nest smart thermostat and ecobee smart thermostat. If you have two to four wires, these thermostats could be a fit for your home.

Nest says its thermostats are designed to require not a lot of power and can often share it with your HVAC system. However, you may need to have a specialist like Air Concepts of Middle Georgia put in a C wire with the Nest Thermostat E or Nest Learning Thermostat if you’re running into power problems or a battery that’s always drained.

ecobee works with 24-volt systems (ones with three to six thermostat wires) and includes a C wire adaptor. So, you’re good if you don’t have a thermostat C wire.

Rely on Air Concepts of Middle Georgia for Your Smart Thermostat Installation Needs

At Air Concepts of Middle Georgia, we’re always seeking approaches to keep you comfier while keeping heating and cooling costs inexpensive. If you want to know more about switching to a smart thermostat without a C wire, contact us at 478-200-5689. We can help you select the right model for your residence and even install new wiring if needed.