Regarding your water hammer. Do you know what you water pressure is? PSI should be from 40 to 80, and in my opinion at least, 80 if still too high. Since pressure can vary, you really need to check it frequently at different times of the day, or better yet, get a gauge with a tattle tale needle. If it is too high appliances like the washer, dishwasher, humidifiers, ice makers, and toilets can develop problems. A pressure regulator would be in order in those cases, along with a thermal expansion tank. Many not be your problem, but worth checking.