Hotpoint refrigerator model #HSM25GFRF SA water dispenser?

Our refrigerator's door water dispenser freezes. How can we prevent this? We use it at least 20 times daily. Our fridge is about 75% full and set at 5. The freezer is usually 75-90% full and was set at 5. My son checked the celluloid & it's good. He turned off the water & unplugged the hose at the bottom of the door which ran clear. He turned the freezer down to 3 & it defrosted itself. It worked great for about a month but it's frozen again. Also, there's only 2 of us so sometimes the ice cube tray gets really full & I must empty some of it. Could that be part of the problem? Do we have too much in the freezer?