Mains-powered with relay and OpenTherm outputs. Provides flexibility with universal operation and optional smartphone control. 3-wire installation. Includes manual override facility, backlit LCD display, frost protection and holiday mode. Works with iOS & Android Apps 5-30°C Temperature Range Suitable for All Boilers 3-Wire Installation Mains-Powered Backlit LCD Display 7 Day, 5/2 Day or 24 Hour Programmable 3 Pre-Set Programmes 8 On / Off Periods per Day Boost Facility Works with iOS & Android Apps 5-30°C Temperature Range Suitable for All Boilers 3-Wire Installation Mains-Powered Backlit LCD Display 7 Day, 5/2 Day or 24 Hour Programmable 3 Pre-Set Programmes 8 On / Off Periods per Day Boost Facility