The invention relates to a process to control a steam unit (2) of a domestic appliance (1), which steam unit (2) produces water steam, especially hot or superheated water steam, which is fed to a treatment area (3), especially to a drum, and which steam unit comprises at least one steam generator (4) with a heating element and water supply means to supply water to the steam generator. The process according to the invention is characterized in that the temperature (24) of the steam generator (4), especially the surface temperature of the steam generator (4) and/or the temperature of the heating element of the steam generator, and/or the temperature of the water steam is measured, and in a normal operation the heating element of the steam generator (4) and/or the water supply means (5) are controlled in such a way that the measured temperature (24) is kept between a given lower temperature limit (30) and a given upper temperature limit (31).