How To Upgrade To A Smart Thermostat With Four Wires

b. If you don’t have a common wire, Ross recommends wiring the G wire into the common port instead. Most people don’t use the “fan only” mode, so while you’d give up control over the fan in the system, you’d gain constant power to the smart thermostat. You’ll also have to change the wire at the furnace from G to C. 5. Connect the thermostat to the baseplate. 6. Configure the thermostat following the manufacturer’s settings.

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Ross installed a Google Nest Thermostat E. The kit comes with the baseplate, thermostat, and required screws to secure it to the wall.

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