I Want a Smart Thermostat but Don't Have a C Wire - What Are My Options?

June 09, 2021

When you’re wanting methods to lower energy expenses, getting a smart thermostat is a smart idea. These devices pick up on your favorite temperatures and routine and then develop an energy-efficient schedule that fits. What’s even better is that you can change and monitor your settings from almost anywhere with your phone, whether you’re lying in bed or out and about. (You might even be able to receive a free smart thermostat depending on rebate programs from your utility supplier in Lincoln.)

In many instances, adding a smart home thermostat with the help of AW Heating & Air Conditioning is an uncomplicated process if you have a more modern residence. But what if your house is older or doesn’t have the proper wiring? Can you still have a smart thermostat without C wire? We’ll help you figure out the process so you can choose the ideal thermostat and enjoy energy savings for many years.

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

The majority of programmable thermostats run on batteries. When you’re switching to a smart thermostat, you’ll find 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 find out if you have a C wire by doing the following:

  1. Cut power to the thermostat at the breaker.
  2. Take off the thermostat and look at 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. Ensure the C wire isn’t hidden inside 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 specifically 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 isn’t right and you don’t want to put in new wiring.

Do Nest or ecobee Need a C Wire?

Two of the top brands are the Nest smart thermostat and ecobee smart thermostat. If you have two to four wires, these thermostats could work for your home.

Nest says its thermostats are created to require minimal power and can often share it with your heating and cooling system. However, you may need to have a specialist like AW Heating & Air Conditioning put in a C wire with the Nest Thermostat E or Nest Learning Thermostat if you’re having power problems or a battery that’s always drained.

ecobee is compatible 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.

Trust AW Heating & Air Conditioning for Your Smart Thermostat Installation Needs

At AW Heating & Air Conditioning, we’re always looking for methods to keep you cozier while keeping energy bills reasonable. If you have questions about upgrading to a smart thermostat without a C wire, give us a call at 402-438-7992. We can help you choose the right model for your residence and even add new wiring if necessary.