Nest Thermostat Wiring — Diagram 4 Wires -

But to get it right, you need the correct wiring diagram. Let’s break it down simply.

Pull the wires through the Nest base’s center hole. Use the built-in level to make it straight. Screw it to the wall. Nest Thermostat Wiring Diagram 4 Wires -

Here’s the correct mapping: