The RLS/E-MX series of burners are characterised by a modular monoblock structure that means all necessary components can be combined in a single unit thus making installation easier, faster and, above all, more flexible. The series covers a firing range from 1200 to 6155 kW, and they have been designed for use in hot water boilers, overheated water boilers as well as steam boilers. They are equipped with Siemens LMV26, which is able to manage the air-fuel ratio by independent servomotors in order to obtain a perfect output control and to assure a correct combustion and safe operation on all modulation range. Operation can be “two stage progressive” or alternatively “modulating” for both fuels, ligth oil and gas, with the installation of a PID logic regulator. The burner can, therefore, supply with precision the demanded power, guaranteeing an high efficiency system level and the stability setting, obtaining fuel consumption and operating costs reduction. The combustion head guarantees reduced polluting emissions (NOx < 60 mg/kWh on gas operation). An exclusive design guarantees low sound emissions, low electrical consumption, easy use and maintenance.