Turn off power to the thermostat at the furnace/air handler switch or the circuit breaker
Remove the old thermostat cover and unscrew the mounting plate
Label each wire with the terminal it connects to (for example: R, W, Y, G, C)
Disconnect wires from the old thermostat and remove it from the wall
Check that the thermostat location is suitable (indoor, away from direct sunlight, drafts, vents, and moisture)
Mount the new thermostat base/mounting plate to the wall using the provided screws and level it
Connect labeled wires to the matching terminals on the new thermostat
If the thermostat requires a C wire and no C wire is present, install a C-wire solution (add a wire, use an adapter, or use the thermostat’s included power method)
Carefully tuck wires into the wall and ensure no wires are pinched
Install batteries or connect the thermostat to power (if required)
Attach the thermostat faceplate to the base until it clicks or locks in place
Turn power back on at the furnace/air handler or circuit breaker
Set the thermostat mode (heat/cool/auto) and configure system type (single-stage, heat pump, etc.)
Calibrate settings if prompted (fan control, heat stages, temperature limits)
Test heating and cooling by changing the setpoint and verifying operation
Confirm the fan runs as expected (auto/on)
Verify the thermostat displays correct temperature and maintains stable operation
Secure any loose wires and reattach the thermostat cover fully