Smart thermostat setup and the schedule that saves most

What you’ll need

• Photo of your existing thermostat wiring
• Small screwdriver
• The thermostat app

Step by step

1. 1

   Check compatibility and the C-wire

   Remove the old faceplate and photograph the labelled terminals. Most smart thermostats need a common (C) wire or an included adapter.

2. 2

   Kill power to the HVAC system

   Switch the furnace or air handler off at its service switch or breaker before disconnecting anything.

3. 3

   Transfer wires one at a time

   Move each wire from the old terminal to the matching new one individually so nothing gets mixed up.

4. 4

   Run the guided setup

   The app will ask about your system type and test heating and cooling. Let it complete the test rather than skipping it.

5. 5

   Build a realistic schedule

   Set back the temperature while asleep and while out. Small, consistent setbacks beat aggressive ones you override every day.

Energy-saving tips

• Heating and cooling is usually the largest single line on a US electric bill, so this is where scheduling pays most.
• Use the monthly energy report to check whether a schedule change actually reduced runtime.
• Check your utility's website — thermostat rebates are common and often cover a meaningful share of the cost.