Sink drains slow until plunged, then slow again! And a smell...

[mobilejake]

Hi Guys, hope you can give me some ideas.

My kitchen sink is not draining well, it is very very slow (last three months). If i plunge, it lets out loads of air, gurgles and drains very fast. After which i run the water to wash my hands and it is already backing up again! I can plunger it again with the same results and it all becomes a loop!

The second issue, which might be a different problem is that a sulphur smell eminates from under the floor in the next room every time the sink water does actually drain/run. The location of the smell matches where the kitchen sink waste runs and is about 2 meters before it empties into a manhole/inspection chamber under the floor (which is double sealed). Sometimes i can hear gurgling/bubbles half way through the run.

Setup is: Single basin sink > d/w > u-bend >waste pipe > bigger waste pipe > manhole sewer run. No vents or air admittance valves. Is this 2 separate problems?

 

[picasso]

No you have a partly blocked drain, time to get your marigolds on and start cleaning (lovely job)

 

[mobilejake]

Oh no! Its going to be a pain getting things up to clean properly.

But why would there be a smell? I was thinking it must be a separate problem like cracked pipe as the smell is coming from under floor not the kitchen plughole.

 

[London Mike 49]

Boil a couple of kettles of water, one after the other and pour down the plug hole, if there is any fatty deposits in the run it will clear it.
Also run the dishwasher empty on the hottest setting, this helps as well.

You may need to repeat the above a couple of times,

Mike