We have VERY hard water here in Spain, and I use white vinegar to clean the kettle every week :D
Patrice, my iron was playing up so I decided to add vinegar, boy did I make a mess, I have no idea HOW much gunk was in the iron, but it came out so rusty coloured.. I changed the water over and over, kept using the burst of steam and thought I would never get it back to normal it was disgusting, I might try adding vinegar at every fill.....thanks for the tip!!