The CALEFFI CODE^® system can be used to control radiator systems that are part of either independent or centralised systems. This includes medium to large-sized systems such as those in Hotels or Bed and Breakfasts as it can manage up to 64 zones simultaneously through a single Gateway. With the CALEFFI CODE^® system, radiant panel systems (heating only) can also be managed, both independent and centralised, by connecting the Sensor PRO (ambient temperature sensor with boiler contact) code 215002, 215002 BLK to the Caleffi 656 series 24 V electrothermal controls, regulating the temperature of each zone separately.