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

When you’re seeking ways to decrease heating and cooling expenses, getting a smart thermostat is a smart move. These devices learn your favorite temperatures and routine and then make an energy-efficient schedule that fits. What’s even better is that you can regulate and keep an eye on your settings from just about anywhere with your phone, whether you’re sitting in bed or on the go. (You might even be able to receive a free smart thermostat depending on rebate programs from your utility supplier in Warrenton.)

Most of the time, hooking up a smart home thermostat with the help of Schraer Heating & Air Conditioning is a simple task if you have a more modern house. But what if your home is older or doesn’t have the right wiring? Can you still add a smart thermostat without C wire? We’ll help you demystify the process so you can pick the right thermostat and get energy savings for many years.

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

Most programmable thermostats need batteries. When you’re switching to a smart thermostat, you’ll find that many need a C wire, or common wire, for power. If you don’t use this wire, your new thermostat could 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. Remove the thermostat and find the wiring.

3. If there are five or six multicolored wires, you have what’s required for a smart thermostat. You might be pondering 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 close. Ensure 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 designed 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 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 may be a fit for your needs.

Nest says its thermostats are created to run on not a lot of power and can often share it with your home comfort system. However, you may need to have a professional like Schraer Heating & Air Conditioning add a C wire with the Nest Thermostat E or Nest Learning Thermostat if you’re having power problems or a battery that’s always drained.

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

Trust Schraer Heating & Air Conditioning for Your Smart Thermostat Installation Needs

At Schraer Heating & Air Conditioning, we’re always looking for methods to keep you more comfortable while keeping utility costs reasonable. If you want to learn more about switching to a smart thermostat without a C wire, give us a call at 636-456-5041. We can help you select the right model for your house and even add new wiring if necessary.