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

June 09, 2021

When you’re looking for ways to reduce heating and cooling costs, upgrading to a smart thermostat is a wise move. These devices pick up on your favorite temperatures 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 supplier in Middletown.)

In many instances, adding a smart home thermostat with the help of SchagrinGAS Company is an uncomplicated task if you have a newer home. But what if your residence is older or doesn’t have the proper wiring? Can you still install a smart thermostat without C wire? We’ll help you demystify the process so you can choose the recommended thermostat and get energy savings for years to come.

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

The majority of programmable thermostats use batteries. When you’re making the move to a smart thermostat, you’ll learn that many have to have 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 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 check the wiring.
  3. If there are five or six multicolored wires, you have what’s needed 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 almost there. Ensure the C wire isn’t rolled up inside the wall. If you can’t find one, we may be able to add 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 run a smart thermostat with an adaptor just 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 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 work for your home.

Nest says its thermostats are designed to need not a lot of power and can typically share it with your home comfort system. However, you may need to have a professional like SchagrinGAS Company 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 works 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 SchagrinGAS Company for Your Smart Thermostat Installation Needs

At SchagrinGAS Company, we’re always seeking ways to keep you more comfortable while keeping utility costs inexpensive. If you have questions about installing a smart thermostat without a C wire, reach us at 302-231-1380. We can help you select the right model for your home and even install new wiring if needed.