Take a picture of your thermostat's wires and apply the optional wire labels. Carefully remove the old mounting bracket.
Wire colors may vary. Not all wires may be used. Match your wires to the labels printed on Insteon Thermostat for Heat Pumps.
Follow the on-screen instructions in the Insteon app to add Insteon Thermostat for Heat Pumps.
When prompted, press and hold the set button until Thermostat double-beeps.