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

June 09, 2021

When you’re wanting ways to lower heating and cooling expenses, installing a smart thermostat is a wise idea. These devices adjust to your favorite temperatures and routine and then develop an energy-efficient schedule to match. What’s even better is that you can regulate and watch your settings from almost anywhere with your phone, whether you’re lying in bed or out and about. (You might even be able to get a free smart thermostat depending on rebate programs from your utility supplier in Hattiesburg.)

In most instances, hooking up a smart home thermostat with the assistance of Oak Grove Heating & Air Conditioning is a straightforward task if you have a newer house. But what if your home is older or doesn’t have the proper wiring? Can you still install a smart thermostat without C wire? We’ll help you figure out the process so you can pick the ideal thermostat and enjoy energy savings for years to come.

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

Many programmable thermostats need batteries. When you’re making the move to a smart thermostat, you’ll learn that many need a C wire, or common wire, for power. If you don’t use this wire, your new thermostat may cause your heating and cooling system to have malfunctions.

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

  1. Turn off 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 needed for a smart thermostat. You might be thinking what color is the C wire on a thermostat—and the answer to that is typically 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 add one for you or you may be able to run your new thermostat without one.
  5. If you have two thick wires, you may be able to install a smart thermostat with an adaptor just for high-voltage systems. Or you may be able to use a battery-powered smart thermostat, like the Lux Geo Wi-Fi Thermostat, if your wiring won’t work and you don’t want to put in 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 could work for you.

Nest says its thermostats are created to run on very little power and can frequently share it with your home comfort system. However, you may need to have a professional like Oak Grove Heating & Air Conditioning install a C wire with the Nest Thermostat E or Nest Learning Thermostat if you’re having power problems or a battery that’s constantly drained.

ecobee is compatible with 24-volt systems (ones with three to six thermostat wires) and comes with a C wire adaptor. So, you’re taken care of if you don’t have a thermostat C wire.

Trust Oak Grove Heating & Air Conditioning for Your Smart Thermostat Installation Needs

At Oak Grove Heating & Air Conditioning, we’re always seeking ways to keep you comfier while keeping heating and cooling expenses inexpensive. If you have questions about upgrading to a smart thermostat without a C wire, reach us at 601-292-9763. We can help you select the right model for your residence and even put in new wiring if required.