Short for “common wire”, a c-wire is an electrical necessity if you’re planning to upgrade your older, no-frills thermostat to a more efficient smart thermostat.

New smart models include features such as Wi-Fi connectivity, remote access from anywhere in the world via a smartphone app or laptop, a bright, multi-functional touchscreen, and energy tracking capabilities. They can even send you text messages to alert you to unusually high or low temperatures inside the home, possible system malfunctions, and also remind you when routine maintenance such as replacing the air filter is required. However, to provide all these extras, these advanced units need more power than the old-school traditional thermostats. More specifically, they require continuous 24-volt electricity to keep the unit fully functional

Which Homes Need A C-Wire?

HVAC systems in many homes were originally wired for conventional battery-powered thermostats that didn’t require continuous 24-volt power. These homes often lack the c-wire that’s necessary to provide power for today’s new, more advanced units. Here’s how the wiring requirements will differ in the most typical scenarios:

  • HVAC systems with traditional four-wire thermostats typically require installation of the extra c-wire to accommodate a smart thermostat.
  • Some newer homes have five wires extending to the thermostat. Generally, one of those wires is the c-wire. In that case, no extra wiring will be needed.

What’s Involved In Getting It Done?

If your house happens to lack that fifth wire, it’s no major problem. While installing a c-wire is definitely not a DIY project, the procedure is familiar to a qualified, experienced HVAC technician. Installation of the new wire completes the circuit that provides continuous 24-volt AC power for your new smart thermostat. It also opens up a wide range of new features for home comfort control and efficiency.

For all your heating and air needs, contact the professionals at Jackson & Sons.