Indirect (fired) heater is a kind of heating equipment especially for oil & natural gas exploitation of oilfield. The heater has a ready-package water jacket structure and consists of the principal section of heater, burner and electrical control system. There are two groups of coil pipe in the heater with the medium processing. With natural gas or light oil as fuel, equipped with advanced full automatic imported burner, explosion proof device for the principal section of heater and water temperature monitoring device, the safe and reliable full automatic operation of heater is ensured.