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

June 09, 2021

When you’re looking for approaches to decrease utility bills, getting a smart thermostat is a smart idea. 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 change and keep an eye on 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 receive a free smart thermostat depending on rebate programs from your utility company in Chadron.)

In most instances, hooking up a smart home thermostat with the assistance of MPC Heating & Cooling is an uncomplicated process if you have a more modern residence. But what if your home is older or doesn’t have the proper wiring? Can you still have a smart thermostat without C wire? We’ll help you demystify the process so you can select the proper thermostat and get energy savings for years to come.

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 discover 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. Remove the thermostat and check the wiring.
  3. If there are five or six multicolored wires, you have what you need for a smart thermostat. You might be thinking what color is the C wire on a thermostat—and the answer to that is often blue.
  4. If there are three or four thin multicolored wires, you’re almost there. Ensure 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 use a smart thermostat with an adaptor specifically 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 isn’t right 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 may be a fit for your needs.

Nest says its thermostats are made to need minimal power and can often share it with your heating and cooling system. However, you may need to have a professional like MPC Heating & Cooling install a C wire with the Nest Thermostat E or Nest Learning Thermostat if you’re experiencing power problems or a battery that’s frequently drained.

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

Depend on MPC Heating & Cooling for Your Smart Thermostat Installation Needs

At MPC Heating & Cooling, we’re always seeking methods to keep you more comfortable while keeping heating and cooling expenses reasonable. If you want to know more about upgrading to a smart thermostat without a C wire, reach us at 308-832-4321. We can help you choose the right model for your residence and even put in new wiring if necessary.