It is a good practice to do calc-clean before heating up the appliance. Do not open the calc-clean cap when the appliance is hot; if the appliance is hot, unplug the power cord from the mains and let the steam tank cool down for 2 hours. Pour away the water from the water tank. Remove the calc-clean cap by turning it anticlockwise. Pour away water from the steam tank into the sink. Rinse the steam tank with tap water until all impurities are flushed out. Screw the calc clean-cap tightly by turning it clockwise. Calc-clean should be done once a month. For more information, check the user manual.