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

June 09, 2021

When you’re looking for ways to reduce heating and cooling bills, getting a smart thermostat is a wise decision. These devices learn your favorite temperatures and routine and then make an energy-efficient schedule that fits. What’s even better is that you can regulate and monitor your settings from just about anywhere with your phone, whether you’re relaxing 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 Beaverton.)

In many instances, installing a smart home thermostat with the support of Garoken Energy Co. Inc. is a simple job if you have a newer home. 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 correct thermostat and get energy savings for many years.

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

Most programmable thermostats need batteries. When you’re making the move to a smart thermostat, you’ll find that many need a C wire, or common wire, for power. If you don’t have this wire, your new thermostat could cause your heating and cooling system to malfunction.

You can ascertain 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 pondering 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 almost there. Check the C wire isn’t tucked inside the wall. If you can’t find one, we may be able to install 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 is incompatible and you don’t want to install new wiring.

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 might be a fit for your home.

Nest says its thermostats are designed to run on minimal power and can frequently share it with your home comfort system. However, you may need to have a professional like Garoken Energy Co. Inc. 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 is compatible 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.

Rely on Garoken Energy Co. Inc. for Your Smart Thermostat Installation Needs

At Garoken Energy Co. Inc., we’re always looking for approaches to keep you more comfortable while keeping heating and cooling costs reasonable. If you want to learn more about switching to a smart thermostat without a C wire, contact us at 503-374-1934. We can help you pick the right model for your residence and even put in new wiring if required.