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

June 09, 2021

When you’re seeking ways to lower utility bills, getting a smart thermostat is a wise decision. These devices adjust to your temperature preferences and routine and then develop an energy-efficient schedule that matches. What’s even better is that you can regulate and monitor your settings from nearly anywhere with your phone, whether you’re relaxing in bed or out and about. (You might even be eligible for a free smart thermostat depending on rebate programs from your utility supplier in Marshfield.)

In most instances, installing a smart home thermostat with the assistance of House of Heating Incorporated is an uncomplicated job if you have a newer 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 navigate the process so you can choose the proper thermostat and enjoy energy savings for a long time.

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

Many programmable thermostats use 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 malfunction.

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

  1. Turn off power to the thermostat at the breaker.
  2. Pull off 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 typically blue.
  4. If there are three or four thin multicolored wires, you’re almost there. Check the C wire isn’t hidden within the wall. If you can’t find one, we may be able to put in 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 designed 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 won’t work 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 an option for you.

Nest says its thermostats are created to consume minimal power and can often share it with your HVAC system. However, you may need to have a professional like House of Heating Incorporated put in a C wire with the Nest Thermostat E or Nest Learning Thermostat if you’re having power problems or a battery that’s constantly drained.

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

Depend on House of Heating Incorporated for Your Smart Thermostat Installation Needs

At House of Heating Incorporated, we’re always on the lookout for methods to keep you cozier while keeping energy bills inexpensive. If you want to know more about switching to a smart thermostat without a C wire, give us a call at 715-384-3163. We can help you choose the right model for your home and even add new wiring if required.