I have a Rowenta steamer and never had a problem and I use tap water in it. I also have a Rowenta iron, but I do use Distilled water in, again no problem. Both these iron/steamer are at least 10 years old. I have a Black n Decker steam iron that I use for applique messes, again no problem. I do not empty any water unless I do not plan on using them for a week or more.