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!

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.

Are you sure it's not the water coming out of the faucet?

Catch some in a bucket/bowl/cup (without letting it go down the drain)
and see if you get the same effect.

Otherwise, does the sink have 'overflow' drains on it? Maybe there's
some funk in there, and the smell stays put until water going into the
drain 'blows' it out the overflow.

Or something.

"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.

Is the overflow drain shared between the sinks? Verify the P trap is full
enough to seal off the pipe. A leak in the pipe for the P trap on top of
the pipe may not result in a water leak but would still be open to the vent.



"Texas Yankee" wrote in message
news:hBt5g.38426$C63.36627@trnddc06...
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!

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.

No, the overflow drain isn't shared between the sinks - and there appears to
be enough water standing in the trap of the sink with the problem so that
there's not an opening where vent gas could come back in. For this reason,
I'm suspect of the vent, versus something that the water heater is doing to
the water - and it's only this one sink - which I (used to) use every day.

"PipeDown" wrote in message
. net...
Is the overflow drain shared between the sinks? Verify the P trap is full
enough to seal off the pipe. A leak in the pipe for the P trap on top of
the pipe may not result in a water leak but would still be open to the
vent.



"Texas Yankee" wrote in message
news:hBt5g.38426$C63.36627@trnddc06...
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!

A double sink might have seperate vents but probably not, if they are close
together, what you do in one is the same as the other. A leaking vent
smells more like an unflushed toilet than it does eggs.

I vote for the poster who suggested there is some kind of funk in the drain
and when you run the water, it displaces that bad air and brings it up to
your nose. Try a little foaming draino and make sure it gets into the
overflow tube. Try snaking the trap and otherwise cleaning the drain.

Also the other poster who suggested the experiment of running the water into
a bucket to determine if it is a drain or supply issue had a great idea.
plug the drain and overflow when you do this to have no doubt. Reverse the
experiment by pouring known clean water down the drain at the normal rate
and see which way elicits the smell.


"Texas Yankee" wrote in message
news:24v5g.2836$c%5.2576@trnddc02...
No, the overflow drain isn't shared between the sinks - and there appears
to be enough water standing in the trap of the sink with the problem so
that there's not an opening where vent gas could come back in. For this
reason, I'm suspect of the vent, versus something that the water heater is
doing to the water - and it's only this one sink - which I (used to) use
every day.

"PipeDown" wrote in message
. net...
Is the overflow drain shared between the sinks? Verify the P trap is
full enough to seal off the pipe. A leak in the pipe for the P trap on
top of the pipe may not result in a water leak but would still be open to
the vent.



"Texas Yankee" wrote in message
news:hBt5g.38426$C63.36627@trnddc06...
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!