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

June 09, 2021

When you’re looking for approaches to decrease heating and cooling bills, getting a smart thermostat is a smart move. These devices learn the temperatures you like and routine and then make an energy-efficient schedule that matches. What’s even better is that you can adjust and watch your settings from nearly anywhere with your phone, whether you’re sitting in bed or on the go. (You might even be able to get a free smart thermostat depending on rebate programs from your utility supplier in Dayton.)

In most instances, installing a smart home thermostat with the assistance of Jent Mechanical LLC is an uncomplicated job if you have a new home. But what if your home is older or doesn’t have the correct wiring? Can you still install a smart thermostat without C wire? We’ll help you demystify the process so you can pick the recommended thermostat and receive energy savings for many years.

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

Many programmable thermostats need batteries. When you’re making the move to a smart thermostat, you’ll discover that many require a C wire, or common wire, for power. Without this wire, your new thermostat might cause your heating and cooling system to malfunction.

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

  1. Cut power to the thermostat at the breaker.
  2. Take off the thermostat and look at the wiring.
  3. If there are five or six multicolored wires, you have what’s required for a smart thermostat. You might be thinking 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 nearly there. Check the C wire isn’t tucked in the wall. If you can’t find one, we may be able to install one for you or you may be able to run 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 use 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 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 you.

Nest says its thermostats are designed to require not a lot of power and can typically share it with your home comfort system. However, you may need to have a professional like Jent Mechanical LLC install a C wire with the Nest Thermostat E or Nest Learning Thermostat if you’re running into 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 covered if you don’t have a thermostat C wire.

Rely on Jent Mechanical LLC for Your Smart Thermostat Installation Needs

At Jent Mechanical LLC, we’re always looking for approaches to keep you cozier while keeping energy expenses low. If you want to know more about installing a smart thermostat without a C wire, give us a call at 937-845-1111. We can help you choose the right model for your house and even install new wiring if necessary.