How long does the steam room take to get hot, and how do I control the temperature? The steam generator should start to produce steam within a couple of minutes, and the room / shower will be comfortable to bathe (35-40°C) within 10-15 minutes (depending on the power rating of the steam generator compared to the size of the room). Most generators come with a thermostatic control which sets and controls the room temperature. If your generator only has an ON/OFF button, you can control the temperature manually. - - - - - - - - - - - - - - - - |