U Bend problem

[stuart]

Recently fitted a kitchen sink into the back room at the office, everything is fine and works properly except for a really smelly U Bend, after being left over night the whole room smells of drains!

I do know that the smell is coming up the plug hole as leaving the plug in overnight and tapeing up the Draining board waste cures the problem or at least stops the smell for that night! however, letting the tap run for a while before leaving doesn't seem to help.

But why is this happening, Have I fitted the wrong type of U Bend for a sink ? Am I missing something really obvious ?

Here is a snap shot of the plumbing

.... Any suggestions ..

BTW There is nothing unusual poured down the sink, just coffee water and milk!

[The3rd Earl Of Derby]

Where is that top section going to? this could be the culprit as the U-bend is adequate for holding clean water.

-- Sir Benjamin middlethwaite

[stuart]

This goes to the draining board part of the sink unit

[Lurch]

On Wed, 28 Sep 2005 23:39:56 +0100, "stuart" scrawled:

All looks OK to me from this angle.

Is there actually any water in the trap when you come to it in a morning? Could be being syphoned out during the night possibly?

[DJC]

siphonage most likely. Do you know where the drain goes to? What else is connected to the system, anything that might be used overnght?

[kitchenman]

This will be a venting problem, simple way to fix it is to get a trap with a vent built in

[John Rumm]

Yup, won't make all those gluggy sounds that the current one does after the sink empties either ;-)

[Dave Fawthrop]

| | Recently fitted a kitchen sink into the back room at the office, everything | is fine and works properly except for a really smelly U Bend, after being | left over night the whole room smells of drains! | | I do know that the smell is coming up the plug hole as leaving the plug in | overnight and tapeing up the Draining board waste cures the problem or at | least stops the smell for that night! however, letting the tap run for a | while before leaving doesn't seem to help.

Where does the sink outlet lead to? It sounds as if it goes straight into the soil pipe with a toilet above the connection. If so the suction from toilet is emptying the U bend, and allowing the drains to vent into the back room. Buy and fit a deeper U bend to the sink. These are manufactured to solve exactly this problem, I have not seen one in a shed, but a plumbers merchant should have them.

[Chris Bacon]

Is there somewhere that water can stand after the draining board but before the U? Try flushing it well with dilute ("thin") bleach, from the sink *and* DB drain, then see if it smells.

[Andy Luckman (AJL Electronics)]

More like a posting problem. See if this throws some light: