The boiler and the machine must always be considered as one unit, because the machine must generate a certain amount of power for its work. But it can only do this if the boiler provides enough energy in the form of steam. If a boiler is too small, the machine will never deliver enough power. Thus, the boiler is actually the most important element of a steam plant. Dieter Miedek shows the way from historical background, theoretical calculations, tools and equipment to the manufacture of a simple steam boiler. Above all, the skill of brazing is an essential craft requirement for building a boiler system yourself. The peripheral equipment required for safe operation around the steam boiler is not neglected either.