Purchase this service only at the direction of our service dept. request. It is not recommended to under the retrofit process if your older white/grey thermostat controller is otherwise working. 

Retrofit process for the newer bluetooth thermostat controller can leave your heater down for a period of time and complications with the upgrade can happen. So do not request this update for the sole reason of getting bluetooth phone app capability. 

You will likely also be required to purchase a new BT thermostat controller separately.