Chapter 1 — What You’re Actually Solving

You’re upgrading from a traditional programmable (or non- programmable) thermostat to a smart one — Nest, Ecobee, Honeywell Home, Amazon, or equivalent. The value prop: remote control, learning schedules, energy reporting, occupancy detection.

The install is mostly electrical (5 thin wires, no 120V), mostly easy — except for the C-wire problem. Which is the whole topic of Chapter 3.

What this book covers

• HVAC thermostat wiring basics (R, W, Y, G, C, and companions).
• Identifying your system (gas, heat pump, dual-fuel, etc).
• C-wire presence/absence diagnosis.
• Install process.
• App setup and scheduling.

What this book doesn’t cover

• Line-voltage thermostats (baseboard electric heat). Different beast. Smart thermostats for those exist but are specialized.
• Multi-zone systems with complex zone controllers. Can often be done but system-specific.
• HVAC troubleshooting beyond thermostat replacement.