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

June 09, 2021

When you’re seeking ways to lower energy costs, getting a smart thermostat is a wise decision. These devices pick up on the temperatures you like and routine and then create an energy-efficient schedule that fits. What’s even better is that you can regulate and watch your settings from almost anywhere with your phone, whether you’re relaxing in bed or out and about. (You might even be able to receive a free smart thermostat depending on rebate programs from your utility company in Litchfield Park.)

In many instances, hooking up a smart home thermostat with the support of Cooler Tymes LLC is a simple task if you have a more modern residence. But what if your house is older or doesn’t have the proper wiring? Can you still have a smart thermostat without C wire? We’ll help you demystify the process so you can pick the recommended thermostat and enjoy 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 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 glitches.

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 look at the wiring.
  3. If there are five or six multicolored wires, you have what’s needed 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 close. Ensure the C wire isn’t hidden inside the wall. If you can’t find one, we may be able to install 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 just 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 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 could be a match for you.

Nest says its thermostats are made to run on very little power and can frequently share it with your HVAC system. However, you may need to have a specialist like Cooler Tymes LLC install a C wire with the Nest Thermostat E or Nest Learning Thermostat if you’re experiencing power problems or a battery that’s constantly drained.

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

Depend on Cooler Tymes LLC for Your Smart Thermostat Installation Needs

At Cooler Tymes LLC, we’re always on the lookout for methods to keep you comfier while keeping heating and cooling costs reasonable. If you want to know more about upgrading to a smart thermostat without a C wire, give us a call at 623-208-6444. We can help you choose the right model for your house and even put in new wiring if necessary.