I Want a Smart Thermostat but Don't Have a C Wire - What Are My Options?

June 09, 2021

When you’re wanting approaches to reduce utility bills, getting a smart thermostat is a smart move. These devices adjust to your temperature preferences and routine and then make an energy-efficient schedule to match. What’s even better is that you can change and keep an eye on your settings from nearly anywhere with your phone, whether you’re lying in bed or out and about. (You might even be eligible for a free smart thermostat depending on rebate programs from your utility provider in Pocatello.)

In many instances, installing a smart home thermostat with the help of Vogts Heating & Air is a straightforward job if you have a new residence. But what if your home is older or doesn’t have the correct wiring? Can you still add a smart thermostat without C wire? We’ll help you demystify the process so you can pick the ideal thermostat and enjoy energy savings for years to come.

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

Most 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. Without this wire, your new thermostat might cause your heating and cooling system to have glitches.

You can determine 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 find the wiring.
  3. If there are five or six multicolored wires, you have what’s needed for a smart thermostat. You might be wondering what color is the C wire on a thermostat—and the answer to that is usually blue.
  4. If there are three or four thin multicolored wires, you’re almost there. Ensure the C wire isn’t tucked within 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 use a smart thermostat with an adaptor just 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 most popular brands are the Nest smart thermostat and ecobee smart thermostat. If you have two to four wires, these thermostats may be an option for your home.

Nest says its thermostats are designed to require not a lot of power and can typically share it with your heating and cooling system. However, you may need to have a specialist like Vogts Heating & Air add 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 works with 24-volt systems (ones with three to six thermostat wires) and comes with a C wire adaptor. So, you’re covered if you don’t have a thermostat C wire.

Trust Vogts Heating & Air for Your Smart Thermostat Installation Needs

At Vogts Heating & Air, we’re always seeking ways to keep you cozier while keeping utility expenses inexpensive. If you want to know more about installing a smart thermostat without a C wire, give us a call at 208-621-0129. We can help you choose the right model for your home and even add new wiring if needed.