I've been unable to solve the low pitched "thunk" noise (vibrating pipes)
that happens when the Fluidmaster 400a shuts off the water after a flush. I
tried reducing the flow at the shutoff valve, but then I got a worse type of
problem of an oscillating bang caused when the toilet shutoff valve closed
beyond a certain point.
I tried shutting off the water altogether and draining the pipes but that
It seems a cost effective solution would be for me to replace the darn
Fluidmaster valve with a Korky Quietfill valve (which does not cause
hammer). Only thing is I hate to having to waste the time replacing the
valve just because of, what, in my opinion, was a bad design choice (if it's
really true that the pipes are being harmed by the abrupt shutoff of the
According to the Fluidmaster website, they make a "whisper" model that
supposedly mitigates water hammer (albeit with a slower fill). I'm
wondering if a good quick fix could be done by swapping the top part of a
"whisper" model??? Or, is there is any other inexpensive modification I
could make to the Fluidmaster that would accomplish the same thing (WITHOUT
having to drain the tank and remove whole)???
(and, no, I don't think it makes any sense have a "hammer arrestor"
installed is much more expensive than simply replacing the toilet valve)