- Q.I am having a problem with a
shower valve in a bathroom remodeling project. When you
turn the water all the way to hot and then back off to
around the middle of the temperature range, you get a
pulsating water flow from the shower head and severe,
loud knocking from the shower pipes in the wall. The
problem does not occur when the valve is opened all the
way, full hot. We've secured the valve and the piping
with clamps. Are you aware of any remedy for this
problem short of taking the tiled walls apart to
install a water hammer arrester?
A.Master Plumber Rex
Cauldwell responds: A water hammer arrester
won't solve the problem; I think the problem is in
the faucet body itself. This type of water
pulsation and the associated water hammer are
typical of faucets with balancing valve assemblies
and check valves. The problem is not limited to one
manufacturer; I've experienced it with several
brands.
You have a choice of pulling the valve cartridge
and checking it for debris or just replacing the
faucet. Most of the time, I replace the faucet,
because, even with new parts, I often can't fix the
problem. I typically switch the faucet to a
Moentrol, by Moen (800/289-6636,
http://www.moen.com); I've had
the best luck with that brand.