Kitchen drainage not draining

[stevedurban]

Hi all

Wondering if anyone can help... We have a kitchen sink which doesn't drain so well!

2 "qualified" plumbers have been to see it - both put new pipe work (1 put the black piece and the other moved the dishwasher connection)

when we we called both back - they said it must be caused by a blockage in the flats plumbing and there is nothing they can do!

However, as a semi logical person, I put the tap over the middle little drainer and turned it on full blast (blocking up the main sink) and no blockage! It Drains at an acceptable speed.

if I don't block up the main sink when I fill the little drainer - the water comes up into the main sink - and drains very very slowly.

Does anyone one have any ideas? I've tried to show it as best as possible here:





Any help would be greatly appreciated!!

thanks in advance!

 

[SimonG]

Gravity is the issue. Water runs downhill. Needs repiping from scratch and one trap.

 

[rpm]

Might want to check the hose from the washing / dishwasher is fully on and consider adding a small jubilee clip.

 

[stevedurban]

Where would the trap be? On the main sink?

I guess the issue to contend with is the main outlet for the waste is roughly inline with the bottom of the sink - and as its a flat, there isn't so much that can be done to move it apparently!

 

[SimonG]

Both wastes connected together. Appliance trap and then to drain.

 

[SimonG]

Looking at it again its def diy. The parts are there to do it properly. Just been put together wrong. Them flexis look strained as well.

 

[stevedurban]

Ok, happy to give it a go!

But, is it a major issue that the outlet is at the same level as the bottom of the sink? How much fall is acceptable to still work?

 

[Riley]

Well the water will carry food, grease and soap scum to name a few. You need enough of a drop that this won't just rest on the bottom half of the pipe. There are much better ways of doing this and it just looks like whoever piped it did so with whatever bits they could find.

 

[stevedurban]

Ok - anyone got any diagrams of the optimal method?

 

[Riley]

McAlpine Double & 1½ Bowl Sink Kit 40mm White | Traps | NoLinkingToThis

 

[plumben]

By the looks of it the waste outlet is to high to start with, if it was my job i'd be re coring a new waste out lower down