In hard water areas it is a good idea to use distilled or bottled water in your steamer. Hard water chemicals found in tap water in some towns may cause limescale build up in the boiler and cleaning tools preventing the product from working effectively. A good source of pure or distilled water is from a condenser tumble dryer. The water collected in tank is ideal to use in the steamer if you also have a condenser dryer. Most supermarkets sell bottled water that is also ideal.