On Wed, 9 Sep 2009 08:07:15 -0400, "Robert11"
wrote:

...

Am tempted to call it a water-hammer, but I always thought water hammer, in
the true sense of the word, was only when one closed a valve, and the
ensuing pressure wave due to the running water being shut, suddenly, caused
the hammer.

You are right and it is not likely waterhammer.

I would tend to believe you have some loose pipes somewhere. I
suggest following the pipes and have someone turn the water on and off
unitl you find the source.

Do you have city water or a well?

If city water do you have any kind of pressure reduction
device?

If well check any pressure tanks.

Does it do it equally on hot and cold water?


Is this true ?

We have no problem when shutting; only when turning it on.

Anyway, I replaced the small hot and cold top-hat rubber seals and their
springs.
No change. Still happens.

But there is a built in water diverter valve that goes to a hose sprinkler
for cleaning pots and pans, I guess.
We never use the hose.

Think this valve might be actuating and causing the problem ?

Hard to see how, as the end of the hose is of course shut off, so even if
the valve actuates, it is leading to a "closed" section of hose. But,...?

Any thoughts on this would be most appreciated.

Thanks,
Bob