On Wed, 30 Jan 2013 15:28:44 -0600, NamPhong
wrote:

Fairly certain have the correct answer but thought to run it past this
group for a sanity check.
When one toilet, and only one toilet, is flushed I get a water hammer
through the ice maker connection to the fridge (all pipes have been
checked and are not loose). Do not get any hammer when other toilets
are flushed and cannot recreate the hammer by shutting off the water
rapidly at any other water outlet.
Is there any adjustment to slow down the closing of the fill valve (new
style with vertical float)in the toilet?
Is best solution to just change the fill valve.
Thanks for the assist.

I think you are on are target about the fill valve. Find the install
instruction for your brand and look for a way to adjust it. Raise or
lower the shut-off height of the float.

You can try to close the water supply a tad and see if the hammer
stops.