Dan Listermann | 2009-07-05 | 7:50:09 AM wrote:

Our cold water faucets always produce an initial stream of hot water
before the cold starts. I believe it has to do with the expansion
tank on the heater. There is a check valve on the water line that
feeds the heater, but the backflow seems to indicate that it does not
work. It is the flapper type and it is pointed down. Is there a
problem with trying to use this sort of check valve in a downward
position? I checked the arrow marking and it appears to be installed
in the right direction.

The initial slug of hot water is probably the water that's in the pipe
in the wall. If it's an outside wall or the pipes run through the
attic, that water can get pretty warm.

After the water in the wall runs through, it's followed by water that
has been underground, or in the basement ceiling, or whatever depending
on how your house is built. Eventually, you get to water that has
_definitely_ been sitting underground.

--
Steve Bell
New Life Home Improvement
Arlington, TX USA