Sulphur smell in the bathroom

[behappy87]

Recently I've noticed that after the tap in the bathroom sink has been running for any length of time (longer than about half a minute), it really starts to smell of sulphur...what could it be and is it bad? Thanks.

[Ethel]

Is it from the cold water tap or the hot tap?

If you can, resist running that particular tap overnight and turn the kitchen tap on first next morning.

Do you still get the smell?

[Alibobs]

We had this problem in a sink that isn't used very often, on investigation it seemed to be coming from the overflow. It was almost as if the running water was disturbing stagnant water further down the system creating the smell.

We used a proprietary drain cleaner and I now make sure I run the tap regularly.

I am not a plumber and have no idea if this is the cause but it seemed to work for us!

[behappy87]

Ethel - it's the cold tap - and it seems like the smell appears regardless of whether or not I've used other taps.

Alibobs - your comment makes sense. This tap isn't used very often, I don't live here all the time - it does often go for a week or so with no use. Which drain cleaner did you use?

Thanks for your comments.

[Clanad]

If it's used that infrequently, it's probable that the water in the "goose-neck" water trap under the sink is simply drying out. It's designed to hold water in the "U" bend to keep sewer gases frpm returning up the drain pipe. If left for a while the water simply evaporates and the gases come up. It is dangerous since the gases can contain methane which is, of course, flammable. The smell is produced by hydrogen sulfide which in large amounts is toxic...

The reason you smell it near the overflow inlet in the sink is that the overflow re-enters the drain just above the trap described above...

[Alibobs]

behappy - only just read your post. I don't remember which one, - it cost about a fiver and came from a DIY store