The article deals with the issue of the scale of the scale on the heating elements of mobile steam generators (puus), which are widely used in the oil and gas industry for the deparaffination of wells, pipelines, oil and gas and other equipment with a high-pressure and low pressure steam, as well as for other domestic and industrial needs. Since the operation of steam generating units takes place in the field at a far distance from the main bases of their dislocation (storage and accounting), which leads to the forced consumption of physically and chemically unprepared feed water. Usually it is underground natural spring water, water from the year, lakes, ponds, etc. The work of steam generating units on untreated water leads to the formation of scum, which causes excessive fuel consumption and the operation of the boiler of the steam generator due to the burning of the coil. However, even during the work on prepared cooking water on the walls of the conformed scale, which reduces the efficiency of its work and requires periodic removal with acid treatment in 48-72 hours of installations. Operators, often themselves create conditions for the formation of thick layers of scale and significant fuel overrun to obtain the required amount of steam, compared with the regulatory data regulated instructions for the technical operation of installations. The article analyzes the influence of the thickness of the scale of the scale on the heat losses of the boiler and the influence of the scale of the scale on fuel overload by a mobile steam generator. The mathematical dependence of excess fuel consumption on the thickness of the scale of the scale is obtained. It has been shown that the occurrence of scale causes not only economic but also environmental problems. It is analyzed the effect of scum on fuel consumption by mobile steam generator units (STU) in the article. The methods of removal which aim to fuel economy are offered.