On 6 Jul 2006 09:05:00 -0700, wrote:

just wanted to check if I have diagnosed this correctly.
When hot water is being drawn used in the house
(like in a shower) the inlet to the recirc pump, which is
next to the water heater in the garage, starts to run very
cold. I assume this is not normal and must mean that the
recirc pump is broken in some way?

my issue is that when taking a hot shower in a bathroom that
is closest to the water heater, the water turns very cold in parts
of the house that are further from the water heater (but closer
to the return pipe for the recirc pump). i.e. water in one shower
is nice and hot while water in the other shower is very cold
when both are running. the "cold" shower returns to nice and
hot when it is on by itself. I replace valves that could be causing
mixing and/or turned off secondary shutoffs and nothing worked.
Only thing I notice now is that the return pipe going to the recirc
pump gets very cold when I have both showers on and then one
of the showers run cold.

is there anything else i should try to make sure its the recirc
pump or not? My water heater is less than 2 years old and since
I get steaming hot water during this problem I assume its not the
issue.
recirc pump is 9 yrs old.

Assuming that you are very wealthy and want to keep the energy
wasting recirc pump, then hire a plumber to check it out.

I'd guess that either you have a restriction in your lines (calcium
buildup), or you bought a way too small water heater.

The recirc pump should shut off when you are taking a shower and
using hot water. Most new installations I see either have a on/off
buttion near the sink/shower or a timer.

And you probably need more than one recirc pump, or better yet,
insulate and increase the size of your hot water line.