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

June 09, 2021

When you’re looking for approaches to decrease utility costs, getting a smart thermostat is an intelligent decision. These devices learn your favorite temperatures and routine and then develop an energy-efficient schedule that fits. What’s even better is that you can change 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 get a free smart thermostat depending on rebate programs from your utility provider in West Columbia.)

Most of the time, adding a smart home thermostat with the help of Tri City Fuel & Heating Co., Inc. is an uncomplicated process if you have a newer residence. But what if your house is older or doesn’t have the correct wiring? Can you still install a smart thermostat without C wire? We’ll help you navigate the process so you can select the correct thermostat and receive 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 upgrading to a smart thermostat, you’ll find that many require 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 malfunction.

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 wondering what color is the C wire on a thermostat—and the answer to that is often blue.
  4. If there are three or four thin multicolored wires, you’re nearly there. Check the C wire isn’t hidden 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 operate 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 use 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 most popular brands are the Nest smart thermostat and ecobee smart thermostat. If you have two to four wires, these thermostats may work for your needs.

Nest says its thermostats are created to run on not a lot of power and can often share it with your HVAC system. However, you may need to have a specialist like Tri City Fuel & Heating Co., 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 always drained.

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

Trust Tri City Fuel & Heating Co., Inc. for Your Smart Thermostat Installation Needs

At Tri City Fuel & Heating Co., Inc., we’re always on the lookout for approaches to keep you comfier while keeping heating and cooling bills inexpensive. If you have questions about switching to a smart thermostat without a C wire, give us a call at 803-265-4208. We can help you pick the right model for your residence and even install new wiring if needed.