Burners for heavy oil at three stages, fan at high pressurization, combustion head with adjustment at high efficiency and high flame stability complete of servomotors for the opening of the air shutters, suitable for heavy oil up to 20°E to 50°C and for BTZ heavy oil. Disposition rationalized of the components with accessibility facilitated for the operations of setting and maintenance. Complete of flange and gasket for installation on boiler, nozzles, flexible pipes, line filter electrically heated and equipped with a thermostat.