Its clogged. Turn off the ice maker by flipping up the bar. Leave it off for about an hour. Then turn off the water at the valve - away from where it enters into the back of the fridge - if not on the line before the wall then see if there is one under the sink usually the line ends there. After the water is off, get a bucket and pull the icebox out. Try to get the line off - some are threaded, others have a nut attached - a few are pressure fitted - meaning they are 'plugged in' depends on the make, model and age of the ice maker (not always the same thing as the make and model of the icebox ;-)) If you can get the line off, then check the end - it is possible that there is stuff there. If not then get a look see inside the icebox part of the line - check for ice. If there is ice you will need to call a specialists there is more than one problem. If you can see no blockage then still calla specialist - because its more or less a problem at the ice maker and due to make and model and age of those a whole variety of different things could be going on. If you have hard water then the culprit is hard water deposits which may require taking the ice maker out of the freezer and dismantlement it partially soaking the distribution point the bit that puts water in each 'cup' of the tray in vinegar. If its the hose that has clogged (there are hoses inside of ice makers - they usually are best replaced since they are too difficult to get really cleaned out of mineral deposits. Soaking in vinegar for 20 to 30 minutes then rinsing under warm running water for about 3-5 minutes should get all the vinegar and mineral off. A toothbrush may come in handy to get the chunks off. If you can't figure out how to take the ice maker unit out, or how to dismantle it call a repair man. We gave up on ice makers long time ago with the well - every six months I had to dismantle it and clean it I got tired of that after the first 5 years - ;-)