Purpose of vent under sink? Discussion Thread
There are bad smells that come from my sink drain when I run water.
On inspecting (undoing) the U-bend trap, there is no debris or anything in there. It is a clean run. And I don't think the water is being siphoned out of the U-bend (though I can't be certain) because the sink is used a lot and the smells occur when I run water, not when I leave it alone.
I was puzzled as to the purpose of the vent that points upward and to the left in the attached picture. It seems to be on the wrong side of the U-bend to be an air admittance valve, and I don't see how it can help at all since air is already free to enter through the sink plugholes.
On inspecting this vent (valve?), it was full of smelly gunk (second attached picture), so I think it's this that is causing the smell. Is there any reason this vent can't be eliminated, using a short section of pipe without the T-off to replace existing section?
Thanks in advance for any advice.
Purpose of vent under sink? for the original thread on Plumbers Forums
There are bad smells that come from my sink drain when I run water.
On inspecting (undoing) the U-bend trap, there is no debris or anything in there. It is a clean run. And I don't think the water is being siphoned out of the U-bend (though I can't be certain) because the sink is used a lot and the smells occur when I run water, not when I leave it alone.
I was puzzled as to the purpose of the vent that points upward and to the left in the attached picture. It seems to be on the wrong side of the U-bend to be an air admittance valve, and I don't see how it can help at all since air is already free to enter through the sink plugholes.
On inspecting this vent (valve?), it was full of smelly gunk (second attached picture), so I think it's this that is causing the smell. Is there any reason this vent can't be eliminated, using a short section of pipe without the T-off to replace existing section?
Thanks in advance for any advice.
Purpose of vent under sink? for the original thread on Plumbers Forums
