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

June 09, 2021

When you’re wanting ways to reduce heating and cooling bills, installing a smart thermostat is a wise idea. These devices learn your favorite temperatures and routine and then create an energy-efficient schedule to match. What’s even better is that you can regulate and monitor your settings from nearly anywhere with your phone, whether you’re relaxing in bed or away from home. (You might even be eligible for a free smart thermostat depending on rebate programs from your utility provider in Northglenn.)

In most instances, hooking up a smart home thermostat with the assistance of Northglenn Heating & Air Conditioning, Inc. is a simple job if you have a more modern house. But what if your home is older or doesn’t have the correct wiring? Can you still have a smart thermostat without C wire? We’ll help you figure out the process so you can choose the ideal thermostat and get energy savings for a long time.

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 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 have glitches.

You can ascertain 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 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 nearly there. Ensure the C wire isn’t tucked 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 use 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 install a battery-powered smart thermostat, like the Lux Geo Wi-Fi Thermostat, if your wiring isn’t right and you don’t want to replace it.

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 be an option for your home.

Nest says its thermostats are designed to need not a lot of power and can frequently share it with your home comfort system. However, you may need to have a specialist like Northglenn Heating & Air Conditioning, Inc. add a C wire with the Nest Thermostat E or Nest Learning Thermostat if you’re experiencing power problems or a battery that’s constantly drained.

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

Depend on Northglenn Heating & Air Conditioning, Inc. for Your Smart Thermostat Installation Needs

At Northglenn Heating & Air Conditioning, Inc., we’re always on the lookout for methods to keep you cozier while keeping heating and cooling expenses inexpensive. If you want to know more about switching to a smart thermostat without a C wire, give us a call at 303-452-4146. We can help you select the right model for your house and even put in new wiring if required.