In our area in Wisconsin we have hard water and lime sets in the iron and tea kettles in no time. I don't use any water in my iron. I use a spray bottle and have good luck pressing anything I want to work on. If I need more steam, I used a thin cloth dishtowel and spray it with water or wet it and use it.
I have had too many spots of dirt and whatever come shooting out of the iron when using water in it.
Carol J.