When choosing a boiler, pay close attention to the material from which it is made. The most durable and reliable material is cast iron. For example, during the operation of cast -iron boilers for at least twenty -five years, there is no problem of burning the boiler and its corrosion. Cast iron boilers will be able to reliably serve you for more than fifty years, but when they are used, it must be remembered that cast iron is a very fragile material that can crack with a strong impact or when cold water enters the boiler. Steel boilers are much less susceptible to deformation and blows, but they are unlikely to last you without repair for more than ten years.