Robert Spike wrote:

I just had a new hot water heater installed a week ago. The plumber
recommended an Expansion Tank, and he installed one of those as well.

Everything is fine. However, once my shower is turned off, or a
toilet is flushed and fills back up, I still hear water flowing
through my pipes through out the house for about 30 seconds or so.
Nothing is leaking anywhere, and this behavior did not exist before
the new hot water heater and new Expansion Tank were installed. My
plumber is baffled. He came out and replaced the Expansion Tank
(thinking that was the problem) but it hasn't helped.

Any idea why this is happening? Is it the new Expansion Tank and, if
so, is this normal behavior?

Please feel free to post here, or e-mail me directly at
.

Thanks.

It could indeed be due to the exp tank, but it's not
necessarily a problem.

If the system pressure drops considerably with useage
(toilet refill, etc.), water will be forced *out* of the
exp tank. When the toilet has filled, the pressure builds
again and now the exp tank fills up.

You might experience this on a well pump system; less likely
on city water unless there is a restriction which drops
pressure markedly.

Jim