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

June 09, 2021

When you’re looking for approaches to lower heating and cooling expenses, installing a smart thermostat is a smart decision. These devices pick up on your temperature preferences and routine and then create an energy-efficient schedule that matches. What’s even better is that you can regulate and keep an eye on your settings from nearly anywhere with your phone, whether you’re sitting in bed or away from home. (You might even be eligible for a free smart thermostat depending on rebate programs from your utility supplier in Saint Petersburg.)

In most instances, hooking up a smart home thermostat with the assistance of Hale's Air Conditioning Services Inc is a straightforward process if you have a newer house. But what if your home is older or doesn’t have the correct wiring? Can you still add a smart thermostat without C wire? We’ll help you navigate the process so you can pick the ideal thermostat and receive energy savings for a long time.

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 require a C wire, or common wire, for power. If you don’t have this wire, your new thermostat might cause your heating and cooling system to have malfunctions.

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

  1. Cut 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 you need 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 inside the wall. If you can’t find one, we may be able to add 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 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 won’t work and you don’t want to replace it.

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 might be a fit for you.

Nest says its thermostats are made to need very little power and can frequently share it with your heating and cooling system. However, you may need to have a professional like Hale's Air Conditioning Services Inc add a C wire with the Nest Thermostat E or Nest Learning Thermostat if you’re having power problems or a battery that’s constantly 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.

Rely on Hale's Air Conditioning Services Inc for Your Smart Thermostat Installation Needs

At Hale's Air Conditioning Services Inc, we’re always seeking methods to keep you more comfortable while keeping heating and cooling expenses low. If you want to know more about upgrading to a smart thermostat without a C wire, reach us at 727-369-6195. We can help you choose the right model for your house and even put in new wiring if necessary.