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

June 09, 2021

When you’re wanting ways to decrease energy costs, upgrading to a smart thermostat is an intelligent move. These devices pick up on the temperatures you like and routine and then develop an energy-efficient schedule that fits. What’s even better is that you can adjust and monitor your settings from nearly 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 provider in Boynton Beach.)

In many instances, adding a smart home thermostat with the assistance of A2Z Air Inc is a straightforward task if you have a new residence. But what if your house is older or doesn’t have the proper wiring? Can you still install a smart thermostat without C wire? We’ll help you demystify the process so you can choose the recommended thermostat and receive energy savings for many years.

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

Many programmable thermostats need batteries. When you’re upgrading to a smart thermostat, you’ll find 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 have glitches.

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

  1. Cut power to the thermostat at the breaker.
  2. Remove 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 thinking what color is the C wire on a thermostat—and the answer to that is usually blue.
  4. If there are three or four thin multicolored wires, you’re close. Make sure the C wire isn’t tucked 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 just 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 won’t work and you don’t want to put in new wiring.

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 might be a match for you.

Nest says its thermostats are made to run on very little power and can often share it with your home comfort system. However, you may need to have a pro like A2Z Air Inc 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 frequently 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 good if you don’t have a thermostat C wire.

Trust A2Z Air Inc for Your Smart Thermostat Installation Needs

At A2Z Air Inc, we’re always looking for approaches to keep you cozier while keeping utility costs inexpensive. If you want to learn more about installing a smart thermostat without a C wire, reach us at 561-270-6228. We can help you choose the right model for your home and even add new wiring if necessary.