Common Wire Installation

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If your Greater Toronto and Hamilton Area thermostat doesn’t have a Common wire, you’ll need to run a new cable from your furnace to your thermostat to install most of the modern smart thermostat models. Our experienced pro technicians can install your common wire for most standard HVAC systems.

What is a Common Wire?

The C wire, also known as the c-wire or “common wire”, enables the continuous flow of power to your thermostat. Today's connected models, though, with Wi-Fi connections and full-color screens, often need more than a simple AA or AAA battery. Thermostats like Nest, Honeywell and the Ecobee may require additional power from the C wire, a fifth wire that provides the negative charge needed to supply enough power for those newer features.

A common wire is simply a wire that's dedicated to delivering constant power to your thermostat. Unlike the other wires connected to your thermostat it doesn't control heating or cooling functions. We are a Toronto and Greater Toronto Area area company which specializes in smart thermostat, such as nest or ecobee, installation and service, which includes common wire installation.

If you experience odd heating or cooling behaviors after installing a smart thermostat ( it's always on won't turn on turns off and on unexpectedly etc.) a C wire may help in some cases. But there may be other issues as well. The best solution is to contact us. They can diagnose and help fix any issues, and connect a C wire or a C wire accessory, to your Nest thermostat if necessary.

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Do you need a Common Wire?

Some housesin the Greater Toronto and Hamilton Area have a four-wire configuration -- an R wire (for power), a G wire (for the fan), a Y wire (for A/C) and a W wire (for heat). If you experience issues listed below, you may need a c wire.

  • Heating or cooling is always on, and won’t turn off
  • Heating or cooling doesn’t turn on
  • You repeatedly see a Delayed or Starts in message on your Nest thermostat’s screen (for example: “Heating is delayed for 2:30 mins” or “Starts in 2:30 mins”)
  • Heating or cooling turns on and off intermittently or unexpectedly
  • The system fan is always running or won’t turn on
  • The system fan turns on and off unexpectedly or intermittently
  • Your system is making strange noises: chattering, stuttering, clicking or thumping- this can be caused by your system turning on and off rapidly

We would love to help you with your latest project.

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