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

June 09, 2021

When you’re wanting methods to reduce utility costs, upgrading to a smart thermostat is a smart move. These devices adjust to your favorite temperatures and routine and then develop an energy-efficient schedule to match. What’s even better is that you can regulate and watch your settings from nearly anywhere with your phone, whether you’re relaxing in bed or out and about. (You might even be able to receive a free smart thermostat depending on rebate programs from your utility provider in West Jefferson.)

In most instances, installing a smart home thermostat with the help of West Jefferson Plumbing and Heating, Inc. is an uncomplicated job if you have a more modern residence. But what if your house is older or doesn’t have the proper wiring? Can you still add a smart thermostat without C wire? We’ll help you demystify the process so you can pick the right thermostat and enjoy energy savings for many years.

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

Most programmable thermostats run on batteries. When you’re upgrading to a smart thermostat, you’ll discover that many need a C wire, or common wire, for power. If you don’t have this wire, your new thermostat might cause your heating and cooling system to have glitches.

You can ascertain 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’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 often blue.
  4. If there are three or four thin multicolored wires, you’re close. Make sure the C wire isn’t hidden in the wall. If you can’t find one, we may be able to add 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 specifically 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 most popular brands are the Nest smart thermostat and ecobee smart thermostat. If you have two to four wires, these thermostats could be a match for your home.

Nest says its thermostats are made to require not a lot of power and can typically share it with your home comfort system. However, you may need to have a pro like West Jefferson Plumbing and Heating, Inc. put in a C wire with the Nest Thermostat E or Nest Learning Thermostat if you’re running into power problems or a battery that’s always drained.

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

Trust West Jefferson Plumbing and Heating, Inc. for Your Smart Thermostat Installation Needs

At West Jefferson Plumbing and Heating, Inc., we’re always on the lookout for methods to keep you more comfortable while keeping heating and cooling bills low. If you want to learn more about installing a smart thermostat without a C wire, reach us at 614-450-1575. We can help you choose the right model for your house and even put in new wiring if required.