Dan Listermann 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.



If the "initial stream" starts immediately when the faucets haven't been
opened for an hour or so, then it probably isn't backflow, unless there
isn't much distance between the heater and the faucets.

If it takes several seconds before hot water appears after opening a
cold faucet then your presumption about the check valve may be correct.

Can you try telling what's going on by feeling the cold water piping on
both sides of the check valve while someone else opens a cold faucet?

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10e12 furlongs per fortnight.