While a set industry standard is in place as a guideline for wiring thermostats, including color codes, it may not be relevant to every install. It is important to know your wires before installing a Zen Thermostat, as relying on color isn’t always sufficient. To ensure that wires are installed correctly, it is best to take a photo of the existing wiring. This confirms original wiring, even though the industry standard and corresponding colors may not be relevant. It is also important to photograph the wiring coming from the thermostat to the HVAC unit, to ensure the control board wiring matches the thermostat wiring.
For a more detailed description of wire identification please see the attachment below.