I am having problems with my gas hot water heater. A few months
ago it
worked fine. Now, whenever I turn on the hot water, it starts
out with
good
pressure but immediately drops off to a trickle. The cold
water
pressure
has remained unchanged. I have checked the thermostat vs. the
actual
water
temperature and it heats to the correct temperature (I checked
the
temp at
both the 120 and 130 degree setting). The water line into the
heater
has
an
on/off valve and I have opened and closed it a few times as
well. The
water
is not discolored or smelly. I've even flushed it recently,
and not
much
of
anything came out in the drained water. Any ideas?

We had the same problem and it turned out to be a cheap washer in the
tap that expanded when heated, so as the water got hotter, the flow
was diminished.
neil