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

June 09, 2021

When you’re wanting ways to reduce heating and cooling expenses, getting a smart thermostat is a wise idea. These devices pick up on your favorite temperatures and routine and then create an energy-efficient schedule that fits. 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 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 provider in Moline.)

In most instances, installing a smart home thermostat with the support of Freed Heating & Air Conditioning is a simple job if you have a more modern residence. But what if your residence 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 choose the right thermostat and get energy savings for years to come.

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

Many programmable thermostats need batteries. When you’re switching to a smart thermostat, you’ll learn that many need a C wire, or common wire, for power. Without this wire, your new thermostat might cause your heating and cooling system to have malfunctions.

You can ascertain 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 check the wiring.
  3. If there are five or six multicolored wires, you have what you need 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 close. Ensure 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 install a smart thermostat with an adaptor just 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 replace it.

Do Nest or ecobee Need a C Wire?

Two of the best-selling brands are the Nest smart thermostat and ecobee smart thermostat. If you have two to four wires, these thermostats may work for you.

Nest says its thermostats are created to need not a lot of power and can often share it with your heating and cooling system. However, you may need to have a specialist like Freed Heating & Air Conditioning install a C wire with the Nest Thermostat E or Nest Learning Thermostat if you’re experiencing power problems or a battery that’s always drained.

ecobee works with 24-volt systems (ones with three to six thermostat wires) and comes with a C wire adaptor. So, you’re taken care of if you don’t have a thermostat C wire.

Rely on Freed Heating & Air Conditioning for Your Smart Thermostat Installation Needs

At Freed Heating & Air Conditioning, we’re always on the lookout for approaches to keep you more comfortable while keeping utility bills low. If you have questions about upgrading to a smart thermostat without a C wire, reach us at 309-323-9584. We can help you select the right model for your home and even add new wiring if necessary.