I Want a Smart Thermostat but Don't Have a C Wire - What Are My Options?

June 09, 2021

When you’re wanting ways to lower energy costs, upgrading to a smart thermostat is an intelligent decision. These devices learn your temperature preferences and routine and then create an energy-efficient schedule that fits. What’s even better is that you can change and watch your settings from almost anywhere with your phone, whether you’re lying in bed or out and about. (You might even be able to get a free smart thermostat depending on rebate programs from your utility company in Circleville.)

In many instances, installing a smart home thermostat with the support of Stephen Hurst Pack Heating and Cooling, Inc is a straightforward process if you have a more modern home. But what if your home is older or doesn’t have the right wiring? Can you still install a smart thermostat without C wire? We’ll help you figure out the process so you can select the recommended thermostat and get energy savings for years to come.

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

Most programmable thermostats use batteries. When you’re upgrading to a smart thermostat, you’ll learn that many need a C wire, or common wire, for power. If you don’t have 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. Switch off power to the thermostat at the breaker.
  2. Pull off 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 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 nearly there. Check the C wire isn’t hidden within 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 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 isn’t right and you don’t want to install new wiring.

Do Nest or ecobee Need a C Wire?

Two of the top brands are the Nest smart thermostat and ecobee smart thermostat. If you have two to four wires, these thermostats may be a match for your needs.

Nest says its thermostats are designed to need very little power and can frequently share it with your HVAC system. However, you may need to have a specialist like Stephen Hurst Pack Heating and Cooling, Inc 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 constantly drained.

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

Trust Stephen Hurst Pack Heating and Cooling, Inc for Your Smart Thermostat Installation Needs

At Stephen Hurst Pack Heating and Cooling, Inc, we’re always looking for methods to keep you cozier while keeping utility expenses reasonable. If you have questions about upgrading to a smart thermostat without a C wire, give us a call at 740-474-5940. We can help you choose the right model for your house and even add new wiring if necessary.