Started off by replacing the water lines and valve, purchased from the same site. Thought I'd cured the problem, but no. Next step was to replace the icemaker, which is incredibly simple. Undo 2 screws, pop out the clips give the wiring harness a good tug and the whole lot comes out. Reverse the process to install the new one. In order to get the process going I pressed the test button on the underside of the unit. So far everything seems to be working properly. If you're having the same problem I'd start by changing out the ice maker first, then the water lines and valve if needed. Also don't buy the ice maker lever (shut off arm) like I did. It is already attached to the new ice maker.