A leaky steam iron is more than just an irritation–droplets of water can cause water stains, which may ruin a delicate garment, or require it to be rewashed. Fortunately, there are simple causes and equally simple solutions to the problem.
Temperature of the Iron
Panasonic, a manufacturer of steam irons, addresses the issue of the iron's temperature on its website. If the iron is not hot enough, steam that is produced within the iron will cool as it comes in contact with the soleplate (the metal base of the iron) and will form water droplets. To avoid this problem, keep the iron vertical while waiting for it to warm up and turn off the steam setting when pressing garments using cooler temperatures. Also, according to applianceinsider.com, some irons come with an auto-shut off safety feature, which can cause the iron to cool unexpectedly.
Some irons are engineered to use tap water instead of distilled water. Rowenta irons, for example, will spit and leak if filled with 100 percent distilled water. If the available tap water has a very high concentration of minerals in it, often called "hard water," Rowenta recommends diluting the tap water by 50 percent with distilled water.
Overfilling the iron's water reservoir can cause the iron to leak when you turn it horizontally. Some irons have a line indicating the maximum allowed water level to help prevent this problem. For others, a process of trial and error may be necessary in order to prevent the problem. Try starting with one ounce of water. If the water overflows out of the iron, decrease the amount added on the next trial. However, if the water does not overflow, you may wish to increase the amount of water added the next time in order to lengthen the amount of time between refills.
Tap water contains minerals such as calcium and iron that are dissolved in the water. If you use tap water to fill your iron, you may experience mineral build-up in the iron as the water evaporates as steam, and the minerals remain in the iron. Over time, these minerals can clog the steam outlets and nozzles. To combat this problem, iron manufactures such as Panasonic and Rowenta recommend that you clean your iron regularly with a vinegar solution.
Overuse of Steam
According to Rowenta, the "Steam Burst" feature on their irons needs time to recover between uses. Overuse of this feature can cause problem leakage. If you notice leaking when using this feature, wait a few extra seconds between uses.