The Heil Observer Communicating Control with Wi-Fi capability is more than a standard thermostat.  Here's why.  When installed as part of a complete Observer Communicating systemn, the Observer control can.

Connect system components with just 4 wires
Self-configure with the system upon initial start-up
Communicate with the outdoor unit's built OD temperature sensor
Disply- text-based diagnostic messages
Configure onboard equipment options from the wall control
Check it out on the goheil.com website.