Another significant superiority of cast -iron boilers in their simple repair. Cast -iron heat exchanger, unlike steel, consists of sections. With any damage (burning, breakdown), the section can be replaced with a new. In a steel boiler, the heat exchanger is a single whole. It will have to be completely changed. Another factor significantly affecting the life of the boiler is the resistance to corrosion. Corrosion occurs inside the boiler when the temperature of the walls of the boilers decreases below the «dew point». It is clear that the confrontation of corrosion is very affected by the thickness of the walls of the heat exchanger. Cast-iron heat exchanger is much thicker than steel, therefore, his service life is about 30-40 years.