filterline electric kettle?

I have a filterline electric kettle which will boil but will not shut off. I have taken off the handle and see a spring which is very loose. I am wondering if its looseness is the problem. However I cannot find a way to get it to connect securely to anything. Is that the problem or is it something other than that and is it fixable. I hate to throw it out just because of this as I am very conscious of both waste and also of our environment. I tried to look for a diagramatic on how it might work but was not able to find one. Your help would be most welcome. Thank you. Teresa