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

June 09, 2021

When you’re seeking approaches to lower energy expenses, upgrading to a smart thermostat is a wise decision. These devices pick up on your temperature preferences and routine and then create an energy-efficient schedule to match. What’s even better is that you can change and keep an eye on your settings from almost anywhere with your phone, whether you’re relaxing in bed or away from home. (You might even be able to get a free smart thermostat depending on rebate programs from your utility provider in Lake Worth.)

Most of the time, adding a smart home thermostat with the help of Smyth Air Conditioning Inc is a simple job if you have a more modern home. 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 ideal thermostat and get energy savings for years to come.

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 find that many have to have a C wire, or common wire, for power. If you don’t use 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. Cut power to the thermostat at the breaker.
  2. Remove the thermostat and look at 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 almost there. Check the C wire isn’t hidden inside 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 use 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 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 an option for your needs.

Nest says its thermostats are designed to require not a lot of power and can often share it with your home comfort system. However, you may need to have a professional like Smyth Air Conditioning Inc 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 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.

Trust Smyth Air Conditioning Inc for Your Smart Thermostat Installation Needs

At Smyth Air Conditioning Inc, we’re always looking for methods to keep you cozier while keeping heating and cooling costs low. If you want to know more about switching to a smart thermostat without a C wire, give us a call at 561-533-6066 . We can help you pick the right model for your house and even add new wiring if required.