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

June 09, 2021

When you’re looking for approaches to reduce energy costs, upgrading to a smart thermostat is a wise decision. These devices adjust to your temperature preferences and routine and then make 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 eligible for a free smart thermostat depending on rebate programs from your utility company in Huntingburg.)

In many instances, installing a smart home thermostat with the help of Dearing's Service & Solutions is a simple task if you have a new residence. But what if your home is older or doesn’t have the right wiring? Can you still add a smart thermostat without C wire? We’ll help you navigate the process so you can choose the recommended thermostat and receive energy savings for many years.

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 find that many require a C wire, or common wire, for power. Without this wire, your new thermostat might cause your heating and cooling system to malfunction.

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 check 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 close. 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 run a smart thermostat with an adaptor specifically 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 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 could work for your needs.

Nest says its thermostats are created to need not a lot of power and can often share it with your heating and cooling system. However, you may need to have a pro like Dearing's Service & Solutions install a C wire with the Nest Thermostat E or Nest Learning Thermostat if you’re having power problems or a battery that’s frequently drained.

ecobee is compatible 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.

Depend on Dearing's Service & Solutions for Your Smart Thermostat Installation Needs

At Dearing's Service & Solutions, we’re always on the lookout for methods to keep you cozier while keeping utility bills inexpensive. If you want to know more about switching to a smart thermostat without a C wire, reach us at 812-200-5844. We can help you pick the right model for your house and even put in new wiring if needed.