Kitchen airlock? (+pics)

[Capablebutuneducated]

Hello all,
The kitchen sink in the property we are renting drains really slowly, and I was hoping to remedy or alleviate this with some educated advice.

In addition to draining slowly, the sink also back fills when the washing machine pumps water out.

I have had the initial undersink work apart and none of it is blocked.
Further, there is a one way vent/valve teeing off the undersink waste (that when I open it the water runs away, but will quickly pour out of the valve/vent). I had this bit off and it appears to still work in allowing air one way but not the other.

The whole undersink area seems 'busy', and I wonder if thst is why it backs up and if there is a more straight forward (efficient) way for it to be set up.


From the pics:

• Is the washer plumbed in too early?
• Is that concertina piece overcomplicating things unnecessarily?
• Is the valve/vent the issue and needs replacing?

Obviously as a rental I don't want to be doing loads of work, but if I can resolve it easily myself I would like to.

If anyone can explain why it doesn't drain/how to fix it I will be very grateful.

Thanks.

C

 

[Chuck]

I suspect that the root cause is insufficient fall on the grey waste-pipe that is hidden behind the built in unit. (Can you see where it ends up?) The horrid flexible section and air admittance valve were probably added last in an unsuccessful attempt to fix/prevent the problem you are investigating.

A proper cure will probably involve a lot of work to gain access and make good afterwards, which is probably why it's been left as is.

 

[snowhead]

As Chuck,,
Plus it's quite possible there's a blockage further downstream behind the sink or wherever it joins to a stack or goes out to a drain gulley.
The behaviour of the Auto air vent and the back filling by the washer seems to confirm that there is a partial blockage.
The blockage will be beyond / below where the washer waste joins to the sink waste.

And or the pipework behind there has no or correct fall on it.

 

[Capablebutuneducated]

Thank you, that was some fast diagnosing!

I did try to get pics of the pipe behind the unit, but without much success. What I could see did not look like it was at a steep angle.

Is it worth trying to get one of those rod things down there?

 

[snowhead]

Is it worth trying to get one of those rod things down there?

Yes, pull the white Tee off and go direct into the elbow.

If you have access to a wet vac you may be able to suck the blockage back, it will probably smell tho,,

 

[Capablebutuneducated]

So, we have our answer.

I tried a snake/rod down the waste, but revealed no immediate blockage.

Our landlord called out a 'drain man' and all was revealed. Our waste goes on quite an around the houses route to a shared drain in next doors garden, and some decorative stones and gravel were causing an obstacle. It will likely happen again, but for now we have free flowing water.

Thank you again for all of the advice, viewpoints and suggestions.

Merry Christmas, and good drains to all men.