Install/upgrade a smart thermostat

Trigger

Anytime / upgrade project

Who does it

DIY

Est. time

1-2 hrs

Est. cost

$130-280

Difficulty

●●○○○

Step by step

Turn off power to the HVAC system at the breaker.
Take a photo of existing wire terminals, then label each wire.
Remove the old thermostat base and mount the new base plate.
Connect wires to matching terminals (check for a C-wire; use an adapter kit if missing).
Restore power, attach the thermostat, and follow the app setup.

Video guide

How to Install a Smart Thermostat - This Old House

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See a better technique, a broken link, or a regional building-code note? Contributions will work like a wiki once accounts and review are live.

Bill of materials