The Best Type of Water to Use in a Steam Iron. Regular tap water contains minerals, like calcium, that will build up inside your iron. Even with a water softener, you tap water will still contain trace amounts of minerals that will eventually clog your iron. Distilled water varieties are best for use in irons.Click to see full answer. Likewise, people ask, why should you not use distilled water in an iron?Distilled water rusts out the inside of irons. They have an anti-calcification function designed into them. The reason for distilled water was because well water can be “hard” and cause calcium deposits to build up in the iron — especially in/around the steam vents.Subsequently, question is, is ironing water the same as distilled water? Distilled Water (Pure Water, De-Ionised Water) However, most steam iron manufacturers now recommend not using distilled water by itself as it can cause the iron to spit and leak, but instead use a 50/50 mix with normal tap water. Considering this, is distilled water good for steam irons? You can find a lot of advice online that recommends only using distilled water for your steam iron, arguing that since it’s mineral-free, minerals can’t clog the iron. Others say the irons use normal tap water, but if the water in your area is very hard, mix with half distilled.Can I use bottled water in my iron?the manual states that if your tap water exceeds this level of water hardness, to use bottled spring water. Do not use pure distilled water. Yes, both will ruin your iron. Use bottle water.