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

When you’re seeking methods to decrease heating and cooling costs, getting a smart thermostat is a smart move. These devices pick up on your favorite temperatures and routine and then create an energy-efficient schedule that matches. What’s even better is that you can change and watch your settings from almost anywhere with your phone, whether you’re lying 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 Portland.)

Most of the time, hooking up a smart home thermostat with the assistance of Three Rivers Heating and Cooling is a straightforward job if you have a newer house. But what if your residence is older or doesn’t have the proper wiring? Can you still have a smart thermostat without C wire? We’ll help you figure out the process so you can pick the right 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 run on batteries. When you’re making the move 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. Turn off power to the thermostat at the breaker.
2. Take off the thermostat and find 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 usually blue.
4. If there are three or four thin multicolored wires, you’re close. Check the C wire isn’t tucked in the wall. If you can’t find one, we may be able to install 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 designed for high-voltage systems. Or you may be able to install 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 fit for you.

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

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

Rely on Three Rivers Heating and Cooling for Your Smart Thermostat Installation Needs

At Three Rivers Heating and Cooling, we’re always looking for methods to keep you cozier while keeping utility bills reasonable. If you want to know more about installing a smart thermostat without a C wire, reach us at (503) 739-5400. We can help you choose the right model for your residence and even add new wiring if necessary.