My sister has a 6 year old whirlpool side-by-side which has several issues. The first being the water on the door runs so slow it is just a trickle. I replaced the filter about 6 months ago and it got worse. Now the ice maker, which was replaced the same time as the filter, isn't keeping up. She lives at the end of a dead end road, last house, so there might be a problem with calcium and lime build up? The water feed is 1/4" copper. Help I don't know what the problem could be.