I live in an old house with galvanized pipes. I want to have the hot water pipes repiped to copper, but leave the cold alone. I have had 4 estimates, ranging from $2100 to $4500. Half of the contractors say do both the cold and hot, the other say just the hot. I don't know which is correct. I have good pressure with my cold water fawcets, it's just the hot I'm having trouble with.