Aaron Fude wrote:

Hi,

Since about two weeks ago, whenever someone shuts off the kitchen
faucet on the first floor, the pipes throught the house, all the way
up to the third floor, experience quite a jolt. Since this started
happening abruptly, does that mean that something has come loose
somewhere? And should I be concerned about it?

It's possible that you have air chambers in your plumbing that have
become filled with water so they aren't doing their job. Air chambers
aren't complicated, just a T fitting and an extra length of vertical
pipe above a sink etc. connection that ends with a cap. The air trapped
in the pipe that goes nowhere acts to cushion any water hammer. Over
time the air in the air chamber pipe could dissolve into the water in
the pipes. The solution is to drain all of the water pipes completely,
than turn the water back on to refill and you are all set. Always turn
the water on slowly when refilling house pipes and bleed the air slowly
at the faucets until all of the air is gone.

Draining and refilling would only sold the problem if the original
plumbers did leave air chambers in the pipes inside the walls.