Here is what I would try. Fill the water tank 1/3-1/2 way full with water, then fill it the rest of the way with WHITE VINIGAR. Set the iron to cotton for 15 minutes, then steam an old towel or something for a few minutes. Then if there is any water left drain it out. let the iron cool off and fill the tank with clean water. repeat heating the iron to cotton for 15 minutes, steaming for a few minutes, drain the water, this time you don't have to let the iron cool before using it again.