How does HT 400 SMART ROOM THERMOSTAT WORKS? HT 400 Smart room thermostat with its 0,1-degree measurement accuracy sets your home temperature via application as you desired. You can save up to %30 of your gas bill by preventing boiler work unnecessary. What are the advantages of HT 400 Smart Room Thermostat? - With Smart room thermostat, you can control your home temperature by app wherever you are in the world.- Create daily or weekly programs easily by your Smart Room Thermostat App.- You can choose one of the 6 different modes which suit your situation and control your home temperature. (Home Mode-Sleep Mode-Outside Mode-Program Mode-Location Mode-Manual Mode)- Using Location Mode reduces the temperature of your home when you move away from home or increases the temperature when you approach your home.- Depending on the date range selected from the smart room thermostats mobile application, you can get a historical report of your heating units working hours, the temperature of your home and the outside temperature gracefully.- You can add more than one home to your app and can control all with one app.- You can invite your family members to app and share control of your home.- HT 400 Smart Room Thermostat is only compatible with On/Off boilers.