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 decrease heating and cooling expenses, upgrading to a smart thermostat is an intelligent idea. These devices pick up on the temperatures you like and routine and then develop an energy-efficient schedule to match. What’s even better is that you can regulate and keep an eye on your settings from nearly anywhere with your phone, whether you’re sitting in bed or away from home. (You might even be able to receive a free smart thermostat depending on rebate programs from your utility provider in Delray Beach.)

In many instances, installing a smart home thermostat with the assistance of Kilbourne Heating & AC is a simple process if you have a new home. But what if your residence is older or doesn’t have the right wiring? Can you still add a smart thermostat without C wire? We’ll help you demystify the process so you can pick the proper 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 upgrading to a smart thermostat, you’ll learn that many have to have a C wire, or common wire, for power. If you don’t have this wire, your new thermostat may 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. Take off the thermostat and check 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 typically blue.
  4. If there are three or four thin multicolored wires, you’re close. Check the C wire isn’t hidden inside the wall. If you can’t find one, we may be able to install 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 run a smart thermostat with an adaptor designed 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 is incompatible and you don’t want to install 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 might be an option for you.

Nest says its thermostats are made to require very little power and can typically share it with your home comfort system. However, you may need to have a specialist like Kilbourne Heating & AC install a C wire with the Nest Thermostat E or Nest Learning Thermostat if you’re running into power problems or a battery that’s constantly drained.

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

Depend on Kilbourne Heating & AC for Your Smart Thermostat Installation Needs

At Kilbourne Heating & AC, we’re always seeking methods to keep you cozier while keeping heating and cooling expenses reasonable. If you want to know more about switching to a smart thermostat without a C wire, reach us at 561-287-7071. We can help you pick the right model for your home and even put in new wiring if necessary.