how can i fix dg980 steam iron?

I have this problem. I like this iron and it want to not shut off the steam part of the iron. it continues all the time. like the valve is stuck or need a new one. It has to be electronic what part should i replace. I have the no. to what i think needs to be replaced. it would be ykg 54-99z1 or 106 )a 2501-t855e4 These no came off the part i think need replaceing. Help!