Smell from water basin outlet

[WendyG]

Hi everyone

Am and have been for some time suffering a terrible "musty damp cloth" type smell from washbasin in the bedroom.  No problems with basin, shower and bidet in adjoining bathroom, just this one washbasin.

Only way to stop smell is to keep plug in and block up the overflow hole in the basin.

If anyone has any helpful suggestions I would be nmost grateful.

WendyG

[Patf]

Do you use it regularly? If not it could need water flushing down it often.

Not sure how this works, but I was told that you need to have water in the trap between the sink and the outside drain or fosse. To block smells coming back up.

[Chancer]

As above first but then check that the corrugated pipe between the trap and the overflow is not full of disgusting gunge

[sid]

It sounds as though the "syphon", the u-bend trap, is not working and it's letting the smells back up through the plughole. Either there is no water in it, ( the water forms a barrier), or the water is being sucked out when another sink/shower/bath on the same waste system is emptied. There needs to be an air inlet in the waste system, usually at the end furthest from the mains sewer or fosse. If this is what's happening you can buy a membrane valve to insert in the waste pipe near the basin u-bend, like this one... http://www.sider.biz/produit/raccord-a-coller-avec-anti-vide.1568.1380.html this will let air in a prevent the basin u-bend from being emptied.

EDIT I should have said, the clue is a gurgling, or "glug-glug" sound when another basin etc is emptied.

 

[londoneye]

Just to add what others have said we have buildings we do not use very often and within a week or so of hot weather we have an almighty fosse smell from either sinks or shower (most commonly) where there water has evaporated from u-bend and thus there is no longer a barrier to prevent smell.     However, it does take a time so assuming you are using the basin (most!) days I would have thought it is another cause as already suggested by sid and others.

[NuBeginnings]

Sid ie spot on, we had the same problem added a vent and changed the trap as it was a poor fit no more smell ;-)

I also run the taps every week to make sure the trap does not run dry.

[WendyG]

Thanks everyone - looking forward to a sweet smelling bedroom|

WendyG

[BIG MAC]

Of course if you leave the plug in then the evaporation will be slower and if there is a dripping tap the sink will eventually top up the water seal through the overflow