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

June 09, 2021

When you’re looking for methods to reduce heating and cooling costs, getting a smart thermostat is an intelligent decision. These devices adjust to your favorite temperatures and routine and then create an energy-efficient schedule that matches. What’s even better is that you can adjust and monitor your settings from just about anywhere with your phone, whether you’re sitting 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 Laguna Niguel.)

In most instances, installing a smart home thermostat with the help of Ocean Air Conditioning and Heating is a straightforward process if you have a newer house. But what if your residence is older or doesn’t have the right wiring? Can you still install a smart thermostat without C wire? We’ll help you demystify the process so you can select the right 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 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 have this wire, your new thermostat could cause your heating and cooling system to have malfunctions.

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

  1. Switch off power to the thermostat at the breaker.
  2. Remove the thermostat and find the wiring.
  3. If there are five or six multicolored wires, you have what’s needed for a smart thermostat. You might be pondering 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 tucked inside 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 use a smart thermostat with an adaptor specifically 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 isn’t right and you don’t want to put in 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 could be a match for your needs.

Nest says its thermostats are made to consume 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 Ocean Air Conditioning and Heating add a C wire with the Nest Thermostat E or Nest Learning Thermostat if you’re having power problems or a battery that’s always drained.

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

Depend on Ocean Air Conditioning and Heating for Your Smart Thermostat Installation Needs

At Ocean Air Conditioning and Heating , we’re always looking for approaches to keep you cozier while keeping heating and cooling costs reasonable. If you want to know more about switching to a smart thermostat without a C wire, reach us at 949-525-9119. We can help you pick the right model for your home and even put in new wiring if required.