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

June 09, 2021

When you’re looking for approaches to decrease heating and cooling bills, upgrading to a smart thermostat is a wise decision. These devices pick up on the temperatures you like and routine and then create an energy-efficient schedule that matches. What’s even better is that you can adjust and keep an eye on your settings from nearly anywhere with your phone, whether you’re relaxing in bed or on the go. (You might even be eligible for a free smart thermostat depending on rebate programs from your utility provider in Phoenix.)

In many instances, adding a smart home thermostat with the assistance of Integrity AC & Heating LLC is an uncomplicated task if you have a more modern residence. But what if your residence is older or doesn’t have the right wiring? Can you still have a smart thermostat without C wire? We’ll help you figure out the process so you can pick the proper thermostat and enjoy energy savings for years to come.

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

The majority of programmable thermostats run on batteries. When you’re switching to a smart thermostat, you’ll learn 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 have glitches.

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

  1. Switch off power to the thermostat at the breaker.
  2. Pull off the thermostat and look at the wiring.
  3. If there are five or six multicolored wires, you have what you need for a smart thermostat. You might be wondering 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. Make sure the C wire isn’t hidden 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 use a smart thermostat with an adaptor just for high-voltage systems. Or you may be able to install a battery-powered smart thermostat, like the Lux Geo Wi-Fi Thermostat, if your wiring won’t work 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 fit for your needs.

Nest says its thermostats are created to consume not a lot of power and can typically share it with your home comfort system. However, you may need to have a professional like Integrity AC & Heating 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 always 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.

Rely on Integrity AC & Heating LLC for Your Smart Thermostat Installation Needs

At Integrity AC & Heating LLC, we’re always on the lookout for methods to keep you comfier while keeping energy bills low. If you have questions about installing a smart thermostat without a C wire, reach us at 602-971-0567. We can help you select the right model for your home and even put in new wiring if necessary.