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

June 09, 2021

When you’re wanting approaches to reduce heating and cooling bills, installing a smart thermostat is a smart move. These devices learn your temperature preferences and routine and then create an energy-efficient schedule that fits. What’s even better is that you can adjust and monitor your settings from just about 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 Grove City.)

Most of the time, installing a smart home thermostat with the support of Air Quality Solutions is a straightforward job if you have a newer house. But what if your home is older or doesn’t have the proper wiring? Can you still add a smart thermostat without C wire? We’ll help you navigate the process so you can pick the proper thermostat and receive energy savings for a long time.

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 have this wire, your new thermostat could cause your heating and cooling system to have glitches.

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

  1. Turn off power to the thermostat at the breaker.
  2. Take off the thermostat and check the wiring.
  3. If there are five or six multicolored wires, you have what’s needed for a smart thermostat. You might be pondering 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 rolled up within the wall. If you can’t find one, we may be able to install 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 run a smart thermostat with an adaptor specifically 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 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 may work for your home.

Nest says its thermostats are designed to require not a lot of power and can frequently share it with your home comfort system. However, you may need to have a pro like Air Quality Solutions add 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 connects with 24-volt systems (ones with three to six thermostat wires) and has a C wire adaptor. So, you’re taken care of if you don’t have a thermostat C wire.

Rely on Air Quality Solutions for Your Smart Thermostat Installation Needs

At Air Quality Solutions, we’re always seeking approaches to keep you more comfortable while keeping energy expenses inexpensive. If you have questions about upgrading to a smart thermostat without a C wire, reach us at 614-871-4144. We can help you choose the right model for your house and even install new wiring if needed.