Common ground: A bare or green wire ties the system to the building ground for safety. C terminal: Completes the circuit for continuous power, essential for smart displays and Wi-Fi modules.
Thermostat Wiring Common Mistakes and How to Avoid Them
The R wire carries the positive return from the transformer, while the C wire often connects to the neutral leg to provide a steady 24-volt supply for digital thermostats. G terminal: Activates the blower fan to move air through the ducts.
Thermostat wires: Connect to the low-voltage side, with the R terminal acting as the hot side. Power Sources and the Transformer Most residential thermostats operate on low voltage, which is supplied by a transformer located near the furnace or air handler.
Avoiding Common Thermostat Wiring Mistakes: Ground, C, R, and G Terminals
Transformer Connections Explained Transformer leads: Typically attached to the T and R terminals on the equipment. You will often find this diagram printed on the back of the thermostat, inside the equipment cabinet, or in the installation manual.
More About How thermostats are wired
Looking at How thermostats are wired from another angle can help expand the discussion and give readers a second clear paragraph under the same section.
More perspective on How thermostats are wired can make the topic easier to follow by connecting earlier points with a few simple takeaways.
