dm,

Whistling means there is a restriction in the water line that has a high water velocity through the restriction spot. Is there a particular spot that has the whistling. A valve can be only half open or some type of particle(sand, gravel, etc) stuck in a fitting. Also, it may indicate too high a pressure in the line which can make the velocity excessive. Do some investigating and let us know what you find. Aloha

Thanks for the suggestion. I will work on it in a couple of weeks because my house is being renovated and I am living in a hotel for now. As soon as they are done, I will tear into it.