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

June 09, 2021

When you’re looking for approaches to decrease heating and cooling costs, getting a smart thermostat is a wise idea. These devices learn your favorite temperatures 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 get a free smart thermostat depending on rebate programs from your utility company in Kutztown.)

In many instances, installing a smart home thermostat with the help of Moyer Total Indoor Comfort is a straightforward task if you have a new home. But what if your house 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 select the right thermostat and get energy savings for years to come.

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

Most programmable thermostats use batteries. When you’re making the move to a smart thermostat, you’ll learn that many require 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 have glitches.

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

  1. Switch 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 required for a smart thermostat. You might be pondering 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 almost there. Check the C wire isn’t hidden 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 use 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 most popular brands are the Nest smart thermostat and ecobee smart thermostat. If you have two to four wires, these thermostats might be a fit for you.

Nest says its thermostats are created to require not a lot of power and can often share it with your heating and cooling system. However, you may need to have a professional like Moyer Total Indoor Comfort install 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 works with 24-volt systems (ones with three to six thermostat wires) and includes a C wire adaptor. So, you’re taken care of if you don’t have a thermostat C wire.

Depend on Moyer Total Indoor Comfort for Your Smart Thermostat Installation Needs

At Moyer Total Indoor Comfort, we’re always seeking ways to keep you cozier while keeping utility costs inexpensive. If you want to learn more about switching to a smart thermostat without a C wire, reach us at 484-646-3363. We can help you select the right model for your residence and even install new wiring if required.