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

June 09, 2021

When you’re seeking ways to reduce utility expenses, getting a smart thermostat is a wise idea. These devices learn your favorite temperatures and routine and then create an energy-efficient schedule that fits. What’s even better is that you can change and monitor 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 Hasbrouck Heights.)

In most instances, hooking up a smart home thermostat with the assistance of ACE Solutions is an uncomplicated process if you have a newer residence. But what if your residence 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 select 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 run on batteries. When you’re making the move 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 might cause your heating and cooling system to have malfunctions.

You can find out if you have a C wire by doing the following:

  1. Switch off power to the thermostat at the breaker.
  2. Take off the thermostat and check 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. Ensure the C wire isn’t hidden in the wall. If you can’t find one, we may be able to add 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 install 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 is incompatible 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 needs.

Nest says its thermostats are created to consume minimal power and can often share it with your heating and cooling system. However, you may need to have a professional like ACE Solutions put in a C wire with the Nest Thermostat E or Nest Learning Thermostat if you’re experiencing power problems or a battery that’s always drained.

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

Trust ACE Solutions for Your Smart Thermostat Installation Needs

At ACE Solutions, we’re always looking for methods to keep you more comfortable while keeping heating and cooling costs reasonable. If you have questions about switching to a smart thermostat without a C wire, give us a call at 201-579-2562. We can help you select the right model for your home and even install new wiring if needed.