Kitchen Sink drain problem

[carolus67]

The problem I have is that after waste water drained a smell of bad eggs pervades the kitchen.

The drain is via a U-bend water trap, which I have ensured is clean. However , it seems the trap may not be holding water (otherwise why the odours), but I cannot be sure of this.

A feature of the design of the U-bend which I cannot fathom, is that immediately at the start of the drain just before the U-bend there is a what I can only describe as an additional horizontal U- bend ie this is part of the design!

To me the latter seems to provide no obvious benefit and may be interfering with the action of the trap by causing the trap water to syphon away-somehow!!

An explanation of the conundrum would be much appreciated.

 

[seco services]

have you got a pic

 

[carolus67]

Here's a picture of the U-bend

Untitled

• carolus67
• 8 Aug 2008
• 1

 

[seco services]

all the black tube is because they have a waste fitting on the base of the sink for a sink with an overflow.

is this a bowl 1/2 sink ? as i can see which looks like another bowl in the pic.

have you got a bigger pic of all the sink wastes.
if their is another trap it may be pulling the water out of the other trap.

 

[carolus67]

Hi Seco,

Yes, you are correct the sink is more of a quarter sink than a half sink. The main sink has a waste disposal unit (orange). The black down pipe is joined to the disposal outlet black pipe at the bottom of the picture. The disposal outlet has no separate U-bend.

Untitled

• carolus67
• 8 Aug 2008
• 1

 

[seco services]

your waste disposal (the orange unit) waste is going straight into the waste pipe (black pipe) it should have a trap on it to stop smells coming back.
your smells will be coming back through the waste disposal.

 

[carolus67]

Additional information:

We have been in the house for around seven years, and some years ago I cleaned out the disposal, which it turned out to be mostly unnecessary.

Over the past year or so the disposal has not been used and kitchen waste is disposed of via the 'bin'

The smell is only occasionally but has become more frequent over the past few months. For the first few years there was no smell issue.

The smell definitely comes from the small sink drain not the main sink unit.

Thanks for your deliberations

 

[carolus67]

PS

One point I forgot to mention:

I believe the waste goes to the sewer, and the smell seems to me to be sewer gas !

 

[seco services]

i would run water in the 1/2 bowl then turn tap off then place a bowl under trap and unscrew the bottom of trap to see if the water trap is still there or empty.

if your not ever going to use the waste disposal i would remove and convert back to a normal sink waste.
if you use it or not its still wrong it hasn't got a trap.

 

[carolus67]

Thanks for your advice.