I'm about to remodel the shower and am thinking of replacing the old valve
with a pressure balance valve. Is an anti-scald valve the same as a
pressure balance valve with a hot water limiter?

I don't know if they are the same. But they do the same thing.


Why is the limiter needed? If the water is too hot, wouldn't it be better
to lower the temperature at the hot water heater instead of restricting
the hot water at the valve?

Other applicances, in the house (dishwasher, wash machine) may require
hotter water than the shower so you want to have your heater hot enough for
them. Also the extra heat, at the heater, will enable you to use less hot
water, in the shower, so you can take more showers without running out of
hot water.

Is there any reliability issues with these valves?

Don't know

Some of these valves have only one control that increases both the
waterflow and water temperature, apparently the waterflow is increased to
the max very early on and subsequent turning of the handle adjust only the
ratio of hot water. I prefer being able to adjust both the temperature and
the waterflow. But looking at the spec it's hard to tell if it allows
controlling both the temperature and water flow.

The cold water is turned on first and that is incresed in volume. Than the
hot is added as you open more. This lets you fill a bucket (mopping) with
cold or warm. You cannot use the hot alone or at a low flow rate. If you
need to do this you need to get a 2 handle valve.

E.g.
http://www.homedepot.com/prel80/HDUS...cm_ite=froogle