Recently I've read several bloggers lamenting the loss of their irons. I bought my iron around 1998 and fortunately it is still going strong.
As I was re-reading the directions for cleaning my iron, this was the information they suggested -
Rowenta irons are designed to be used with regular tap water (up to 12 grains of hardness). If your water is harder than this, Rowenta recommends mixing half tap water with half distilled water. Never use 100% pure distilled water since this can cause the iron to spit and leak.
There are many types of household water softeners. Many of them are perfectly acceptable for use in an iron. HOWEVER, some types of softeners, particularly those that use chemicals such as salt, can cause the iron to leak or spit during use. If you experience this type of problem, we recommend that you try using inexpensive bottled spring water. NEVER USE 100% PURE DISTILLED WATER. Once you have changed water it will take several uses to correct the problem.
I know some gals have been experiencing major problems with leaky irons. These are suggestions from the Rowenta cleaning kit, but they may be applicable to other brands as well.