Smelly Kitchen Sink

[crtinson]

I know this kind of things has been covered before but I can't find the answer to my problem.

We are getting sewage smells coming up through the kitchen sink. It is a 1 1/2 bowl sink with twin waste and a spigot to which is attached a dishwasher. The waste has a nice deep U-bend which is full of water and is clear.

The waste goes into the soil stack. The soil stack terminates in the bathroom with a one-way vent. I've taken this vent off and it doesn't look blocked. There are also vents on the sinks in both bathrooms.

When water is run in the sink the smell comes up. For some minutes after the water drains away there is a loud buzzing noise almost a vibration. I guess this is air forcing it's way somewhere.

Any clues how I can solve this?

Also I am about to replace the sink in the ensuite with a vanity unit. When I rebuild the waste is it necessary to fit a vent again? I can't see them in the screwfix catalog.

 

[chrishutt]

The buzzing, vibrating noise is probably an AAV (air admittance valve) operating. Sometimes these are built into traps, sometimes waste pipe size (40mm) and sometimes soil pipe size (110mm) - look here for examples.. If you can identify the culprit (could also be sourse of smell), you could try cleaning it or replacing it.

 

[crtinson]

The buzzing, vibrating noise is probably an AAV (air admittance valve) operating. Sometimes these are built into traps, sometimes waste pipe size (40mm) and sometimes soil pipe size (110mm) - look here for examples.. If you can identify the culprit (could also be sourse of smell), you could try cleaning it or replacing it.

Okay I'll try replacing the valve on the main stack to start with.