Doug Kanter wrote:

"Pete C." wrote in message
...
Texas Yankee wrote:

I have double bathroom sinks - separate p-traps going into the wall for
each
sink - each time I turn on the water in sink #2, there's a distinct
rotten
egg smell, very briefly, that goes away once the water has been running
for
a second or two - looking down into the trap from above the sink, before
I
turn the water on, I can see standing water, so there's no sewer gas
coming
in that way, right? What else should I check? Thanks!

#2 sink doesn't get used very often? Single handle faucet? Try turning
it all the way to cold and see if you get the smell. Most likely a
buildup of hydrogen sulfide on the hot water side while it's sitting
unused. Not much you can do about it other than using the faucet more
frequently. The hydrogen sulfide is generated in your water heater in
tiny amounts, but when the water sits for a while it can separate and
build up.

Pete C.

How long is "a while"? I get the same smell, but the faucet's used 8-10
times a day.

I think it varies relative to the water chemistry in your area and the
condition of the sacrificial magnesium anode in your water heater. I'm
not a chem expert, but I recall the hydrogen sulfide is created by a
reaction with the magnesium anode. Now that I think of it I think you
may be able a get an alternate aluminum anode that doesn't produce the
hydrogen sulfide, but doesn't protect as well.

In my case I notice the HS if I've been away a few days, or if I use the
rarely used kitchen sink sprayer. If you get the HS all the time you may
be more sensitive to it or more HS may be generated in your water
heater. Might be worth investigating the alternate anode material.

Pete C.