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

June 09, 2021

When you’re looking for ways to lower utility bills, upgrading to a smart thermostat is a smart idea. 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 adjust and monitor your settings from just about anywhere with your phone, whether you’re lying in bed or out and about. (You might even be able to receive a free smart thermostat depending on rebate programs from your utility supplier in Paxinos.)

Most of the time, hooking up a smart home thermostat with the support of LTS Plumbing & Heating Inc. is a simple job if you have a new residence. 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 navigate the process so you can choose 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 making the move to a smart thermostat, you’ll discover that many need a C wire, or common wire, for power. If you don’t use this wire, your new thermostat may cause your heating and cooling system to have malfunctions.

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 you need for a smart thermostat. You might be wondering 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 tucked within the wall. If you can’t find one, we may be able to put in 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 run a smart thermostat with an adaptor designed 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 won’t work and you don’t want to install 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 an option for your home.

Nest says its thermostats are made to need not a lot of power and can often share it with your HVAC system. However, you may need to have a pro like LTS Plumbing & Heating 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 frequently drained.

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

Trust LTS Plumbing & Heating Inc. for Your Smart Thermostat Installation Needs

At LTS Plumbing & Heating Inc., we’re always seeking methods to keep you cozier while keeping energy bills reasonable. If you have questions about upgrading to a smart thermostat without a C wire, contact us at 570-648-0748. We can help you choose the right model for your house and even add new wiring if needed.