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

June 09, 2021

When you’re seeking approaches to decrease energy expenses, upgrading to a smart thermostat is an intelligent move. These devices adjust to your favorite temperatures and routine and then develop an energy-efficient schedule that fits. What’s even better is that you can regulate and watch your settings from nearly anywhere with your phone, whether you’re relaxing in bed or on the go. (You might even be able to get a free smart thermostat depending on rebate programs from your utility supplier in Muldrow.)

Most of the time, adding a smart home thermostat with the support of Air Service Co. is a straightforward process if you have a more modern home. But what if your house is older or doesn’t have the right wiring? Can you still install a smart thermostat without C wire? We’ll help you navigate the process so you can pick the recommended thermostat and receive energy savings for a long time.

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

Most programmable thermostats run on batteries. When you’re making the move to a smart thermostat, you’ll discover that many have to have a C wire, or common wire, for power. If you don’t have this wire, your new thermostat might cause your heating and cooling system to malfunction.

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

  1. Turn off power to the thermostat at the breaker.
  2. Pull off the thermostat and look at the wiring.
  3. If there are five or six multicolored wires, you have what’s required for a smart thermostat. You might be wondering 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 close. Make sure the C wire isn’t hidden within the wall. If you can’t find one, we may be able to put in one for you or you may be able to use your new thermostat without one.
  5. If you have two thick wires, you may be able to run a smart thermostat with an adaptor just for high-voltage systems. Or you may be able to operate a battery-powered smart thermostat, like the Lux Geo Wi-Fi Thermostat, if your wiring isn’t right and you don’t want to install new wiring.

Do Nest or ecobee Need a C Wire?

Two of the best-selling brands are the Nest smart thermostat and ecobee smart thermostat. If you have two to four wires, these thermostats might work for you.

Nest says its thermostats are created to run on very little power and can typically share it with your HVAC system. However, you may need to have a pro like Air Service Co. put in a C wire with the Nest Thermostat E or Nest Learning Thermostat if you’re experiencing power problems or a battery that’s frequently drained.

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

Depend on Air Service Co. for Your Smart Thermostat Installation Needs

At Air Service Co., we’re always seeking ways to keep you more comfortable while keeping heating and cooling bills inexpensive. If you have questions about installing a smart thermostat without a C wire, give us a call at 918-212-8943. We can help you select the right model for your residence and even add new wiring if necessary.